The traditional electrical field sensing can be realized by utilizing electro-optic materials or liquid crystals, and has limitations of easy breakdown, free assembly and difficult measurement of low-frequency. Here, we propose a new method to realize safe measurement of spatial dynamic electric field by using a micro fiber interferometer integrated with gold nanofilm. The energy of the electric charge received through antenna forms the intrinsic electric field with two micro electrodes, one of which is the 120 nm gold film vibration beam micromachined by femtosecond lasers and integrated with the micro fiber. The change of the intrinsic electric field force due to the spatial electric field will cause the vibration of the film beam. By demodulating the output signal of the micro fiber interferometer, the electric field can be measured. We demonstrate the detectable frequency ranges from tens of Hz to tens of KHz, and the minimum electric field intensity is ~200 V/m at 1 KHz. Our electric field measurement technology combining optical fiber interference with gold nanostructures shows the advantages of security, high sensitivity, compact size, and multiplexed multi-point and remote detection. Electric field sensing is important for the prevention of electromagnetic interference232 of the minimum detectable electromagnetic energy flux density) for ref. 22232415161820In recent years, the optical electric field detection61314151617181920141516171819201415161718Considering that most low frequency electric field sensing are employed in the electric power system, it’s very important to realize safe measurement of low-frequency electric field with high sensitivity. For the first time, we propose a new method to make a sensor by integrating the antenna and the optical fiber whose detectable frequency ranges from tens of Hz to tens of KHz. The minimum detectable electric field intensity is ~200 V/m at 1 KHz, and the maximum is about 5 kV/m according to the half-wave electric field intensity. The sensitivity can be further improved by modifying the structure and the parameters of the antenna . The key component of the sensor is the micro fiber interferometer integrated with gold nanofilm. The sensing is achieved through the micro area in the sensor with strong electric field formed by the coupling between the antenna and the space electric field. The gold nanofilm can function as the electrode of the micro area, meanwhile, it deforms under the ultra-weak electrostatic force caused by the strong electric field. The vibration beam formed by the gold nanofilm can be the reflector of the Fabry-Perot (F-P) interferometer. Hence, the change of the space electric field can be detected through demodulating the change of cavity length of the interferometer under the electrostatic force.The measurement system to detect the near space electric field is shown in The structure of the sensor is shown in Kslope. The operating wavelength is determined as 1540.5 nm and the corresponding amplitude of output voltage is 2.0 V.For the exploration of suitable operating wavelength, the reflection spectrum of the F-P interferometer is measured and shown in Egap is independent of the gap area Sgap, but is proportional to the amplitude of external spatial electric field intensity Eext. The amplitude of electrostatic force is proportional to the product of Egap and Sgap. Besides, Egap is almost inversely proportional to the gap length Lgap according to Ipeak and the peak external space electric field intensity Eextpeak  as equation It should be noted that only the near-field low-frequency electric field distribution is considered in the absence of magnetic field. To quantitatively describe the sensor’s characteristics of electric field sensing, we have simulated the induced electric field intensity with different structural parameters see . It can εgap is the relative inductivity of gap (here it is 1), ε0 is the permittivity of free space, L is the equivalent antenna length that depends on the structure of antenna (except the gap length) and the insulated packaging material as well as their relative inductivity ε and gap εgap. The optimal L approximate to the total length of two sections of antenna, D is the stiffness factor of the vibration beam, and Lfp is the cavity length of F-P (here it is 37.4 μm) interferometer.where The low-frequency electric field experiment is carried out when the frequency ranges from 30 Hz to 27 KHz with maximum electric field intensity of 3600 Vpp/m, and the experimental results are shown in Eext, the phase of Egap has a phase lead, whereas ΔI has a phase delay due to the mechanical characteristics of the gold film vibration beam. These two opposite effects cause the light intensity change has almost the same phase with the electric field intensity at intermediate frequency, however, has a phase lead at low frequency and a phase delay at high frequency . We can explain the decrease of the response at low frequency around 0 Hz from the point of impedance. When the resistance of the glass bushing of the sensor is assumed to be infinite, the sensor has good amplitude-frequency response around 0 Hz. However, in reality, the resistance of the glass bushing is finite, and it’s even smaller than the capacitive reactance of the sensor, which results in the smaller impedance of the sensor considering the parallel connection of the resistance and capacitance. Hence, around 0 Hz, the strong insulating external air occupies much more voltage than give it to the sensor if we considering them along the electrodes of electric field source in a voltage dividing model. The frequency response around 0 Hz can be flat by using the packaging material with higher resistivity. We also can understand the response of the sensor from the viewpoint of the phase relationship. It is the parallel connection of the resistance and capacitance that leads to the high-pass filtering effect of the sensor, i.e., compared with ency see . By tream and γ are the equivalent mass and damping coefficient of the vibration beam respectively. com(fre) is the function to compensate the amplitude and frequency simultaneously. When electric field generating source is assured, com(fre) can be calculated through m and γ are determined. In actual applications, since period instead of DC signal is what we attempt to measure, there is no need to use the non-modulated light signal which carried notable noise as the zero electric field reference point. Instead, according to the square relation between ΔI and Eext, we can use a medium intensity electric field and the sensor’s corresponding output value of light signal change for calibration, to find out the intensity of target electric field.where Based on the parameters of the sensor, the upper limit of the frequency response is ~20 KHz. The faster charge and discharge rate compared with the deformation velocity of the beam, which is implied by the existence of peak response at high frequency, indicates that upper limit of the frequency can be further increased by reducing the mass of the center of vibration beam and the cavity air resistance (vacuumization) or the designing of higher stiffness factor connection of golden film. The minimum detectable electrical field intensity is ~200 V/m  in the frequency range between 1 KHz to 12 KHz, which will be bigger at lower frequency but smaller at higher frequency. It can be improved by enlarging the external size of the antenna pole, especially the length, or by reducing the length of gap within the sensor. It can be estimated that the minimum detectable deflection of vibration beam is ~1 nm, according to the light intensity noise of the interferometer in the sensor. If the length of internal gap is decreased to 1 nm, whereas the size of the antenna is kept unchanged, with Equation –11 to 10–9 N according to the internal electric field intensity , air resistance power consumption (<1 nW), and sensor resistance heat . With the property of miniaturization and small cross affection with electric field source or environment, our sensor is suitable for directional space electric field sensing or even three-dimensional sensing if three sensors are assembled in different orientations.Additionally, the electrostatic force generated on the vibration beam ranges from 10sity see . The maxnsor see , and corIn summary, we have demonstrated the feasibility of a new method to realize safe measurement of spatial dynamic electric field by using a micro fiber interferometer integrated with gold nanofilm. Although the equivalent driven internal electric field intensity is in the same class as existed optical sensing mechanisms, the external to internal electric field gain factor of our sensor could be bigger than any other optical sensors through the narrowing of the gap length towards 1 nanometer scale without principle constraints . The actual transformer ratio and phase characters have been pre-measured to figure out the high voltage output of transformer. The high voltage is used to generate the required medium to high intensity electric field. The electric field intensity around the sensor is calculated from the simulation of the electric field distribution.The end of stainless steel capillary  is covered with a whole piece of gold film. It is fabricated by a femtosecond laser with high-precision processing platform. The central wavelength of femtosecond laser is about 790 nm. The repeat frequency rate of pulse is 1 KHz. And the focused spot size is ~3 μm. The energy of laser pulse is adjusted to be just enough for gasifying the gold (~1 μJ) to ensure the smooth edge of beam.How to cite this article: Zhu, T. et al. High sensitive space electric field sensing based on micro fiber interferometer with field force driven gold nanofilm. Sci. Rep.5, 15802; doi: 10.1038/srep15802 (2015).


The role of fathers in the development of obesity in their offspring remains poorly understood. We evaluated associations of missing paternal demographic information on birth certificates with perinatal risk factors for childhood obesity.Data were from the Linked CENTURY Study, a database linking birth certificate and well-child visit data for 200,258 Massachusetts children from 1980–2008. We categorized participants based on the availability of paternal age, education, or race/ethnicity and maternal marital status on the birth certificate: (1) pregnancies missing paternal data; (2) pregnancies involving unmarried women with paternal data; and (3) pregnancies involving married women with paternal data. Using linear and logistic regression, we compared differences in smoking during pregnancy, gestational diabetes, birthweight, breastfeeding initiation, and ever recording a weight for length (WFL) ≥ the 95th percentile or crossing upwards ≥2 WFL percentiles between 0–24 months among the study groups.11,989 (6.0 %) birth certificates were missing paternal data; 31,323 (15.6 %) mothers were unmarried. In adjusted analyses, missing paternal data was associated with lower birthweight , smoking during pregnancy , non-initiation of breastfeeding , and with ever having a WFL ≥ 95th percentile . Similar associations were noted for pregnancies involving unmarried women with paternal data, but differences were less pronounced.Missing paternal data on the birth certificate is associated with perinatal risk factors for childhood obesity. Efforts to understand and reduce obesity risk factors in early life may need to consider paternal factors. The prevention of obesity is a national and global health priority , 2. In tMany perinatal risk factors implicated in childhood obesity lie within the family context . MaternaOne valuable source of paternal data is birth certificates. Researchers have reported associations of missing paternal demographic information on the birth certificate, often conceptualized as a proxy for limited paternal involvement, with inadequate prenatal care , pregnanWe used data from the Linked CENTURY Study, a longitudinal electronic health record database linking birth certificate and well-child visit data for 200,343 Massachusetts children ages 0 to <18 years. Details of the Linked CENTURY Study are available elsewhere . BrieflyInstitutional Review Board approval for the CENTURY Study was obtained from Boston College, Harvard Pilgrim Health Care (HPHC), MDPH, and the Massachusetts General Hospital for Children.N = 368 or 0.2 %) missing paternal data where the mothers also reported being married, so we collapsed the groups with missing paternal data to create 3 exposure categories. Removing these cases from the sample had no appreciable impact on our findings (data not shown).To create our main exposure variable, we categorized our study population based on the availability of paternal age, education, or race/ethnicity and the woman’s marital status on the birth certificate as: (1) pregnancies with missing paternal data; (2) pregnancies of unmarried women with paternal data available; and (3) pregnancies of married women with paternal data available. Accounting for marital status allowed us to independently assess the impact of paternal factors on our dependent measures. There were relatively few birth certificates  maternal smoking during pregnancy ; (2) whether the mother had gestational diabetes (data available from 1996 through 2008); (3) birthweight; and (4) whether the mother was breastfeeding at the time the birth certificate was completed . We also examined the prevalence and change in children’s age- and sex-specific weight for length (WFL) z-scores in the first 24 months of life using clinically measured length and weight during the well-child visit. We specifically examined: (1) whether the child ever recorded a WFL at or above the 95th percentile; and (2) whether the child crossed ≥2 major WFL percentiles in any of the following 4 six-month periods in the first 24 months of life: 1–6 months, 6–12 months, 12–18 months, and 18–24 months. This measure that has been associated with later obesity in the CENTURY cohort .Covariates from the birth certificate included child sex and gestational age at birth. We assessed several maternal characteristics that are associated with our outcomes of interest, including: age (<35 years versus ≥35 years); race/ethnicity ; parity (nulliparous versus multiparous); education ; and insurance status (private versus other).We first obtained means and percentages to describe the sample characteristics. We then used unadjusted and multivariable adjusted linear and logistic regression to examine the likelihood of maternal smoking during pregnancy, gestational diabetes, infant birthweight, breastfeeding initiation, and having a WFL at or above the 95th percentile or crossing upwards of ≥2 WFL percentiles between ages 0–24 months for two groups of pregnancies: (1) those with missing paternal data; and (2) those with paternal data where the mother reported being unmarried. Pregnancies of married mothers with paternal data available comprised the reference group. The first model estimated the unadjusted associations. The second model adjusted for child’s sex and gestational age at birth; model 3 additionally adjusted for maternal age, parity, and race/ethnicity; model 4 additionally adjusted for smoking during pregnancy; model 5 additionally adjusted for maternal education, and model 6 added maternal insurance status. We assumed that any diagnosis of gestational diabetes occurred prior to delivery, so we did not adjust for gestational age at birth in our multivariable model of gestational diabetes. Our models of maternal smoking during pregnancy did not adjust for gestational age at birth. As a sensitivity analysis, we then restricted the sample to a more recent time period (2004 to 2008); this modification did not influence the interpretation of our results  so we prN = 11,989) of birth certificates were missing paternal data and 15.6 %  of mothers were unmarried. The vast majority of pregnancies with available paternal data involved married mothers (89.6 %); 10.4 %  of pregnancies with paternal data involved unmarried mothers.Overall, 6.0 %  than pregnancies belonging to the group of married mothers with available paternal data. These pregnancies were also marked by lower birthweights  and an elevated odds of ever having a WFL ≥ 95th percentile  and crossing ≥2 WFL percentiles before 24 months of age . Among pregnancies without paternal data, adding maternal measures to the model (Model 3), resulted in a notable increase in the odds ratio of smoking during pregnancy  and a significant association for the odds of gestational diabetes . Adjustment for smoking during pregnancy in Model 4 slightly lowered the likelihoods of breastfeeding initiation  and gestational diabetes  and reduced infant birthweight . The point estimate for maternal smoking during pregnancy was attenuated after adjustment for maternal education in Model 5  and insurance status in Model 6 . Adjustment for these factors also resulted in a significant association for the odds of children ever having a WFL ≥ 95th percentile before 24 months of age .Associations for the group of pregnancies with available paternal data involving unmarried mothers were similar to the group with missing paternal data, but the differences were less pronounced. After adjustment for child and maternal factors (Model 3), these pregnancies had increased odds of smoking during pregnancy , lower birthweights , and decreased odds of gestational diabetes  and breastfeeding initiation  than pregnancies involving married mothers with paternal data available. The associations for gestational diabetes, breastfeeding initiation, and birthweight remained significant in the models additionally adjusting for smoking during pregnancy (Model 4) and were slightly attenuated after adjustment for maternal education (Model 5) and insurance status (Model 6).In this large cohort study, the availability of paternal data on birth certificates in Massachusetts was independently related to perinatal risk factors for childhood obesity. In adjusted analyses, we observed higher rates of smoking during pregnancy, lower rates of breastfeeding initiation, and reduced infant birthweight among pregnancies without paternal data on the birth certificate as compared to pregnancies involving married mothers where paternal data were available. We also observed higher odds of children ever having a WFL ≥ 95th percentile and of crossing ≥ 2 major WFL percentiles in the first 2 years of life, although this association was modestly attenuated after adjusting for maternal characteristics. Our results raise the possibility of using missing paternal data on the infant birth certificate as a practical tool to identify children who may be at greater risk for certain perinatal precursors of childhood obesity and suggest that efforts to understand and reduce childhood obesity risk factors in early life may need to consider paternal factors.Our findings are consistent with published reports that relate missing paternal data on the birth certificate with obstetric, pregnancy, and early neonatal outcomes , 20–23 aConsistent with a national study of twin births by Tan et al., we found pregnancies without paternal data tended to occur among mothers who were younger and of black race , charactPrevious studies have found associations between family structure and various aspects of child development, including risk for overweight/obesity , 28, 29.We did not have information about why paternal variables were not reported on the birth certificate, but given the potential legal and financial repercussions of omitting paternal data  , one canThis study has several limitations. First, although vital records are an important resource for identifying factors associated with suboptimal perinatal outcomes, birth certificate data may incorrectly report some information. For example, maternal smoking during pregnancy is under-reported on the birth certificate compared to data on smoking collected on confidential surveys completed postpartum . The birObesity rates among children have substantially increased worldwide over the past 3 decades . The famInstitutional Review Board approval for the CENTURY Study was obtained from Boston College, Harvard Pilgrim Health Care (HPHC), MDPH, and the Massachusetts General Hospital for Children.Not applicable.Data will not be shared. These data have been obtained from the Department of Public Health. As recipients, the authors were permitted to publish any analyses of the data, but not the data itself, due to confidentiality conditions.


Respiratory obstruction and stridor in infants and children are not uncommon. A rare cause of these sometimes life-threatening symptoms is the congenital saccular cyst. Objectives: We present the case of a 5-year-old girl with a cervical tumor, which appeared after a laryngeal endoscopic surgery of a saccular cyst with two relapses and a particular local evolution of its recurrence through the cricothyroid membrane. Material and method: The patient data has been reviewed over the entire follow-up period and a thorough an analysis of her investigations and surgery was performed.Results: The unusual evolution of this case was marked by an atypical exteriorization – not found in the published literature. The surgical approach was external, by paramedian thyrotomy, with no further long-term recurrence.Conclusions: An accurate diagnosis of saccular cysts can be made with the help of medical history, by an endoscopic visualization of the lesion and by the CT-scan imaging of the cervical region. Sometimes, saccular cysts can extend beyond laryngeal limits, determining fluid-filled tumors in the cervical region.  Some theories suggest that congenital anomalies are associated with an abnormal embryonic development of the larynx or an abnormal migration of the fourth branchial arch cells, which may form a sequestrated cyst [3]. Acquired cysts may be due to inflammatory, traumatic, or neoplastic obstruction of the saccular orifice. Their importance comes from producing dysphonia and/ or progressive respiratory distress.Laryngeal cysts are rare, achieved, or congenital benign lesions, which can affect all age groups. Congenital cysts of the larynx are an unusual cause of airway obstruction in newborns . Among these, Down’s syndrome, cystic fibrosis, cerebral palsy, cardiac anomalies, prematurity, hydrocephalus, microcephalus, high arched palate, micrognathia, conductive hearing loss, laryngomalacia, and vocal cord paralysis, are included [15].Some studies reported that 20% to 30% of the laryngeal cysts in infants and children, especially those of the saccular type, have been associated with a variety of other congenital or developmental abnormalities [5].DeSanto, Devine and Weiland classified all cystic laryngeal lesions into saccular, ductal and thyroid cartilage foraminal cysts [1]. A cyst that is radiologically and clinically confined to the larynx can be safely and completely excised endoscopically and is classified as type I. Those with extralaryngeal extension are classified as type II, further divided into IIa  and IIb .Recently, Forte proposed a new classification dividing laryngeal cysts into two types based on their extent and the contained tissue . Several different procedures have been used to treat saccular cysts in children. They range from the minimally invasive endoscopic needle aspiration [11]. Currently, needle aspiration is considered a temporizing method in life-threatening airway obstruction [9]. The repeated aspiration of the cyst with a needle is an atraumatic and successful method of treatment; however, subsequent literature has shown a high rate of recurrence with this method . With this approach, the surgeon opens the saccule at its natural drainage point. This procedure allows a continued decompression. Kirse et al. recently described an endoscopic extended ventriculotomy procedure in which most of the lateral wall of the supraglottis, including the false vocal fold and the laryngeal ventricle, are resected [14]. Several authors have advocated the use of the CO2 laser. CO2 laser-assisted endoscopic treatment consists of the complete removal or extensive marsupialization of the cyst [15]. However, an external approach may be preferred as the first surgical step depending on the size and the location of the cyst [9]. The external approach may be performed through lateral cervical approach [15], laryngofissure or paramedian thyrotomy [9]. To prevent recurrences after repeated endoscopic surgeries, a complete removal of the cyst can be achieved through an external approach [Saccular cysts can sometimes present recurrences, even after an apparently complete excision. The atypical exteriorization into the cervical region, through the cricothyroid membrane, has not yet been communicated in the published literature.The mechanism of cyst development is unknown, but can be linked to local mucous producing glands anatomy. The removal of the cyst can be done easily with a minimum morbidity for the patient, by endoscopy. The recurrence of our patients’ cyst 2 years after surgery showed an incomplete excision technique even if performed by using the operating microscope.The CT-scan imaging, using contrast has an important value in confusing cases, especially in revealing the cyst location, extension, and structure.The external approach of the saccular cysts by vertical paramedian thyrotomy and total removal of the cyst, can avoid the laryngeal mucosa opening and the need for a tracheotomy.The excellent collaboration between several specialists  could yield the best results when dealing with infant/ small children airway disease.


We report on quantitative comparison between the electric dipole energy and the Rashba band splitting in model systems of Bi and Sb triangular monolayers under a perpendicular electric field. We used both first-principles and tight binding calculations on p-orbitals with spin-orbit coupling. First-principles calculation shows Rashba band splitting in both systems. It also shows asymmetric charge distributions in the Rashba split bands which are induced by the orbital angular momentum. We calculated the electric dipole energies from coupling of the asymmetric charge distribution and external electric field, and compared it to the Rashba splitting. Remarkably, the total split energy is found to come mostly from the difference in the electric dipole energy for both Bi and Sb systems. A perturbative approach for long wave length limit starting from tight binding calculation also supports that the Rashba band splitting originates mostly from the electric dipole energy difference in the strong atomic spin-orbit coupling regime. Rashba band splitting in a system with an inversion symmetry breaking (ISB) such as material surfaces and hetero-structures recently has drawn much attention in condensed matter physics community123467H = αL · S − αk(k × L) · Es, where α, L, S, αK, k, and Es are SOC parameter, OAM, spin angular momentum (SAM), coupling parameter for electric dipole interaction, crystal momentum and electric field induced by the ISB, respectively1011It was recently found that the atomic orbital angular momentum (OAM) exists in the presence of the ISB and that it induces an asymmetric charge distribution for non-zero crystal momentumThe existence of the OAM in Rashba bands was shown by tight binding and first-principles calculations9101114To show the importance of the electric dipole energy in a quantitative way, we performed first-principles and tight binding calculations on Bi and Sb monolayers with an external field. Use of monolayers with an external field is to mimic the surface state without dealing with complicated bulk states. This is a simple enough model for the purpose of our research to explore the origin of the Rashba band splitting of the surface states. Both first-principles and tight binding calculations are complementary to each other. The electric dipole energy is estimated by using the wave functions from first-principles calculation, which is not model-dependent, while tight binding calculations allow us to have more intuitive analysis on the band structures and wave functions. The outcome from the interaction between the asymmetric charge distribution and the electric field is responsible for the Rashba band splitting in Bi and Sb monolayers.p-orbitals of Bi or Sb atoms. Bands 1 and 2 are mainly of J ≈ 1/2 character while bands 3 to 6 come from mainly J ≈ 3/2 states. We can see the Rashba splitting in the band structure near the Γ and M points which are time reversal invariant momenta (TRIM) of the triangular lattice. Bi single layer whose atomic SOC is stronger than that of Sb shows a larger Rashba splitting in its band structure, which indicates that the magnitude of the Rashba splitting is clearly related to the atomic SOC strength. Indeed, the Rashba splitting observed at Cu, Ag, and Au surfaces also show such correlation between the atomic SOC and the size of the Rashba splittingWe present in J ≈ 1/2 bands (bands 1 and 2) are antiparallel to OAM while they are almost parallel to the OAM directions in J ≈ 3/2 bands (bands 3 to 6).In We notice that while the OAM magnitude is the largest in the bands 1 and 2, the largest band splitting exists in bands 3 and 4. Therefore, the magnitude of OAM cannot be directly linked to the size of the Rashba band splitting. Instead, asymmetric charge distribution, which results from interference of adjacent atomic orbitals with OAM, is found to be proportional to the size of the Rashba band splitting. Therefore, the overlap between adjacent atomic orbitals is also an important factor in the determination of the asymmetric charge distribution, hence the Rashba band splitting. We believe that the electric dipole moments of the states in bands 3 and 4 become stronger than those in bands 1 and 2 due to larger overlap between adjacent atomic orbitals. We will discuss this issue in more detail below.k = 0.2π/a and 0.4π/a along the Γ-M direction in z-direction. Other bands show rather small asymmetry. So, it can be noticed that the magnitude of band splitting is closely related to the electric dipole moment of a state in the band. Bands 1 and 2 have a shape of pz orbital and therefore small orbital overlap between nearest atoms, resulting in small charge asymmetry, which reveals the importance of the orbital overlap for the formation of the electric dipole. Because of this small electric dipole moment, bands 1 and 2 have small Rashba splitting. Bands 3 and 4 have more charge along the in-plane direction  as well as relatively large in-plane components of the OAM. Therefore they have much larger charge asymmetry along the z-direction and band splitting. The top bands (5 and 6) have small charge asymmetry due to the smallest in-plane component of the OAM. When the crystal momentum k becomes twice larger  for both Bi and Sb layers as varying the crystal momentum k from Γ to M point as shown in L · S. The other is the electric-field screening effect due to charge redistribution in Bi or Sb layers by the external electric field. Mostly, the electric dipole energy difference is larger than the Rashba band splitting in Bi layer. It is mainly because of the screening effect. We confirm that the Rashba band splitting mostly originates from the electric dipole energy difference in both Bi and Sb layers, which are considered as in the strong SOC regime. In the next section, we investigated more on the role of the dipole moment in the Rashba splitting and its correlation to SOC by using tight binding approach.To ensure the origin of Rashba band splitting, we compare electric dipole energy difference (dots) Δp-orbitals while other ones reside in energy levels much far from the Fermi levelWe consider a tight binding model for the triangular lattice which consists of Bi or Sb atoms. The electronic properties of them are well-described by H0 is the hopping processes between p-orbitals on the two dimensional triangular lattice without any external fields, HISB is the ISB term coming from external effects such as electric field or the substrate.where H0 readsThe bare Hamiltonian λ = x, y, z is the orbital index and σ = ↑,↓ is the spin index. The matrix elements where a = 3(3V1−V2)/8, b = 3(V1−3V2)/8 and px or py and pz is forbidden by the symmetry. V1 and V2 represent the σ and π bonding between p orbitals. A set of binding parameters, whose long wavelength limits are expressed by xy-plane is broken so thatWe suppose that the inversion symmetry with respect to the whereλ ≠ z. Here γ measures the energy scale of the applied electric field. Near Γ point, they are approximated to which satisfy h0(0) + hSO(0). As an example, we focus on the lowest two degenerate levels for given tight binding parameters above. The eigenenergy isAt Γ point, one can obtain the analytic solution of and corresponding eigenvectors arewhereh0(k)−h0(0) + hISB(k) can be considered as a perturbation and we obtain effective 2×2 Hamiltonian for those two bands asThen, near Γ point, the other terms where and corresponding eigenvectors arewhere The directions of the OAM of the two lowest bands are opposite to each other when this perturbation scheme is valid.The results on the electronic structures from our tight binding approximation are presented in hISB(k) as a perturbation to explain the splitting of two degenerate multi-orbital bands by the ISB. This is a more general consideration compared with the previous section and its results hold throughout whole Brillouin zone if γ is much smaller than the spin-orbit interaction.In this section, we prove that the band splitting is closely related to the dipole energy difference. Here, we regard Let us denote the Bloch states on two split bands as λ = x, y, z is the orbital index, ϕλ is the real space wave function of pλ-orbital and ησ is the spinor. Then the dipole energy where z direction  should be z so that the integral is an even function in z direction. Then,where ϕλ is an odd function in λ direction. One can note that, when p orbitals, the dipole energy becomeswhere we have used the fact that k isThen, the dipole energy difference, k  α/γ), the eigenvectors for the split bands are just equation Near Γ point  = 2γk in the strong SOC limit while it depends linearly on the SOC in the weak SOC region. Although we only considered the lowest bands, we arrive at the same conclusion in the same way for other ones.Since this is exactly same with the energy splitting ΔIn summary, first-principles and tight binding calculations on Bi and Sb triangular monolayers under electric field have been done as model systems. It is shown that the different asymmetric charge distributions are induced for each band given by Rashba splitting, and their dipole energies are quantitatively calculated under external electric field. The electric dipole energy difference and the split energy by Rashba splitting give remarkable agreement. Also, the tight binding calculation supports that the Rashba splitting originates from the electric dipole energy difference in the strong atomic spin-orbit coupling regime. We show that the electric dipole energy is mainly responsible for the Rashba band splitting.ab initio simulation package (VASP)18−6 eV difference between two sequential steps. First, the volume and internal atomic positions of bulk Bi and Sb were optimized till the internal atomic force becomes less than 10−4 eV/Å. Using this converged cell parameters of aBi = 4.641 Å and aSb = 4.388 Å, we constructed Bi and Sb triangular monolayers under an electric field. We then calculated their band structures, and extracted wave function characteristics as well as charge density at a given crystal momentum k and band index n. The wave function characteristics which were calculated by projecting the orbitals onto spherical harmonics of the atom were used to calculate the expectation values of the OAM at a specific k point. From the charge density around a Bi or Sb atom, we calculated the electric dipole moment of the orbital asTo investigate the surface states of Bi and Sb without bulk state contributions, we considered Bi and Sb triangular monolayers. In order to break the inversion symmetry, we applied an electric field along the direction perpendicular to the layer. For the noncollinear density functional theory (DFT) calculation, we used projector augmented-wave (PAW) method as implemented in the Vienna r is the coordinate vector centered at the atom and ρ(r) is the charge density at r.where How to cite this article: Hong, J. et al. Quantitative analysis on electric dipole energy in Rashba band splitting. Sci. Rep.5, 13488; doi: 10.1038/srep13488 (2015).


The length of time between two successive live births , is associated with child survival in the developing world. Short birth intervals (<24 months) contribute to infant and child mortality risks. Contraceptive use contributes to a reduction in short birth intervals, but evidence is lacking in the DRC. We aimed to investigate the proportion of short birth intervals at the provincial level among young women in the DRC.Data from the Demographic and Health Survey undertaken in the DRC in 2007 were analyzed. Logistic regression and Bayesian geo-additive models were used to explain provincial inequalities in short birth intervals among women of reproductive age and young women. Posterior odds ratio (OR) and 95% credible region (CR) were estimated via Markov chain Monte Carlo (MCMC) techniques. Posterior spatial effects and the associated posterior probability maps were produced at the provincial-level to highlight provinces with a significant higher risk of short birth interval.The overall proportion of short birth intervals among all women of reproductive age (15–49 years) and young women (15–24 years) were 30.2% and 38.7% respectively. In multivariate Bayesian geo-additive regression analyses, among the whole sample of women, living in rural areas , exclusive breastfeeding [1.08 ] and women with primary education [1.06 ], were consistently associated with a higher risk of short birth intervals. For the young women, none of the factors considered were associated with the risk of short birth interval except a marginal effect from the lack of education. There was a spatial variation in the proportion of women reporting short birth intervals and among all women of reproductive age across provinces, with Nord-Kivu [1.12 ], Sud Kivu [1.17 ] and Kasai Occidental [1.18 ] reporting a higher risk of short birth intervals. For young women, the higher risk provinces were Nord-Kivu [1.22 ] and Sud Kivu [1.34 ].This study suggests distinct geographic patterns in the proportion of short birth intervals among Congolese women, as well as the potential role of demographic and geographic location factors driving the ongoing higher youth fertility, higher childhood and maternal mortality in the DRC. A birth interval is the length of time between two successive live births –4. LongeWomen in developing countries have shorter birth intervals than they would personally prefer. The main reason for short birth intervals is that many women in developing countries do not use contraception after birth and therefore are likely to become pregnant once fecundity returns . ContracIn 2008, an analysis of data on 844 837 women from 52 Demographic Health Survey data (DHS) from 52 different countries, showed that 54.3% of the recent two births in developing countries were birth intervals of less than 24 months, with children born in those intervals 2.27 times more likely to die before their fifth birthday compared to children born in intervals longer than 24 months , Sud Kivu [1.17 ], the lowest in Kinshasa , Bas-Congo [0.85 ] and Bandundu [0.88 ]. For the young women, Sud-Kivu [1.34 ] and Nord Kivu [1.22 ] had the highest likelihood of short birth intervals. All other provinces had lower birth intervals, especially Bas-Congo and Bandundu (Tables ], Sud Ki, 0.95], In Figures The aim of this study was to identify birth interval spacing inequalities at the province-level in the DRC. We utilised the 2007 DRC DHS data to model and provided provincial risk factors associated with short birth intervals and also provided spatial patterns of short birth intervals among Congolese women of reproductive age by comparing these patterns with their younger counterparts within the sample.The study is not without limitations. Since our analysis required information on preceding birth intervals of the second children born to the women sampled in the survey excluding the first birth, the analysis was conditioned on women who had at least one child leading to the problem of non-randomness of the selected sample of women. Further, although cluster sampling is a cost-saving measure, without the need to list all the households, statistically, it creates analytical problems in that observational units are not independent. Thus, statistical analyses that rely upon the assumption of independence of households drawn will be no longer valid.However, notwithstanding those limitations, the study shows that more than 30% of births occur within a spacing of < = 24 months. The study does not show an association between the use of modern contraception and birth spacing. Similar results were found in Malawi, Tanzania and Zambia where, further on, the increased use of modern contraceptive methods was not accompanied by a decrease in percentage of short intervals between births . In EthiThe study shows that short birth intervals are equally the same for women in rural and urban areas. Perhaps, the effect of rural–urban residence has been captured by the spatial effects of the province of residence, which points to the importance of the spatial analysis for the DRC. The study is in contrast to the existing literature, which shows that differential access to better social services and information, education and employment opportunities in urban areas have brought about a variation in birth spacing by rural–urban residence , 18. ForThere were differences in birth intervals by age of the mother. Young mothers reported a higher likelihood of short birth intervals than older ones and this finding is similar to studies conducted elsewhere , 19, 20.In summary, the association of short birth interval with the household socio-economic status, and education of the women is not a new finding and has been reported in literature. What is new and novel, using the spatial modelling, is the quantification of the spatial effects by highlighting provinces such as Nord Kivu as a province exposing women of reproductive age and young mothers to a higher likelihood of short birth intervals. The spatial effects of the provinces also capture the residual effects of short birth interval that cannot be explained by the measured factors in the sample. These spatial effects are in addition to the women’s individual risk factors, which is a novel approach. The residual spatial effects in the context of the DRC could represent unmeasured factors such as FP provision and facilities, province specific economic crisis of the health system, the accessibility and affordability of FP services including province specific cultural factors as well as the on-going conflict, which has added a devastating economic impact on the already collapsed health system.Our methods are also able to show clearly the negative nonlinear relationship between a woman’s age and her likelihood of reporting a short birth interval. Finally, the spatial effects are able to disentangle the urban–rural apparent observed association with birth intervals within provinces. Clearly, in the context of a lack of national FP policies and collapsed health system, the advantage of urban areas has been dissolved shown by the captured spatial effects.In conclusion, this study suggests distinct geographic patterns in the proportion of short birth interval among Congolese women, as well as the potential role of demographic, socio-economic and geographic location factors driving the ongoing higher childhood and maternal mortality in the DRC. We found several consistent associations between socio-demographic variables and proportion of short birth interval in a nationwide sample of Congolese women from the 2007 DHS. The geographic analysis showed distinct patterns in the proportion and risk short birth interval across the country’s provinces, pointing to the potential influence of demographic, cultural, socio-economic and environmental factors, as well as to an increasing level of higher fertility rate, which are all driving the ongoing higher childhood and maternal mortality in these settings. Importantly, policy makers and public health practitioners can use this geographic information on short birth interval mapping for planning purposes, educational and family planning programs on birth spacing, but also in the decision making process for the allocation of public resources to the most affected areas of the population, especially for youths in these low-income provinces.


In a recently published paper using space-time satellite data to determine air temperature (Ta), Kloog et al. concluded that Ta during pregnancy was associated with lower birth weight and shorter gestational age in the study population. The results obtained pointed to associations between Ta and birth weight during the last trimester, and between Ta and preterm delivery and low birth weight during the entire pregnancy. These results agree with those obtained by There are many epidemiological studies reporting a nonlinear J- or U-shaped relationship between Ta and health indicators such as mortality  and morbA study conducted in Rome with time-series analysis methodology  showed tThis suggests heat waves are an acute stressor on pregnant women, not the chronic stressor described by Kloog et al. The mechanism is unclear by which high temperatures may increase the risk of preterm birth, but there is evidence in the literature that supports a relationship . This shAlthough Kloog et al. introduced Ta values with linear components, from our point of view introducing Ta as a linear component and not taking into account the effects of heat and cold separately minimizes the authors’ ability to draw conclusions about potential impacts. The effects of high temperatures may be offset by cold temperatures. Therefore, it would be interesting to improve the analysis of Kloog et al. by taking into account the effect of Ta, but separating its effect by warm and cold seasons, especially for days within heat and cold waves.


Women’s health is an important task in society. The aim of this qualitative study that used a phenomenological approach was to explain women’s personal experiences of giving birth in Gonabad city that had positive experiences of giving birth in order to establish quality cares and the related factors of midwifery cares for this physiological phenomenon.The participants were 21 primiparae women who gave a normal and or uncomplicated giving birth in the hospital of Gonabad University of medical sciences. Based on a purposeful approach in-depth interviews were continued to reach data saturation. The data were collected through open and semi-structured interactional in-depth interviews with all the participants. All the interviews were taped, transcribed and then analyzed through a qualitative content analysis method to identify the concepts and themes.Some categories were emerged. A quiet and safe environment was the most urgent need of the most women giving birth. Unnecessary routine interventions that are performed on all women regardless of their needs and should be avoided were considered such as: “absolute rest, establishing vein, frequent vaginal examinations, fasting and early Amniotomy”. All the women wanted to take part actively in their giving birth, because they believed it could affect their giving birth.We hope that the women’s experiences of giving birth will be a pleasant and enjoyable experience for all the mothers giving birth. Many phenomena in the world are common to most human societies for example, birth and death and they seem obvious and natural, but these natural phenomena can be affected by pathological processes. Then, health cares and treatments are needed to improve them; however there are control and treatment techniques in the world of modern medicine . Although, moment of giving birth is considered a happy stage in life and can have a positive impact on women and their mental status as well, but objectively it can leave harmful effects on their emotions and health . The expAlso women’s acceptance and agreement on giving birth process can be effective and influence the process of giving birth; however, there is a little information on this idea, opinion and experience. Understanding of perceived cares from women’s views can increase midwifery staffs’ ability to perform their tasks more appropriately. Considering that pregnancy and giving birth services should not be based on the need of the service provider, but on the need of mother and child. Fear of pain on giving birth has become an epidemic in modern world among pregnant women. More than ever, women are frightened of giving birth and what might possibly go around. Then women, who are afraid of giving birth, need psychological support, obstetric guidance and education. The female’s body is designed to stop giving birth in unsafe situations, and the mother being in a heightened state of fear is a trigger for stopping the process. As it was said and understood, mothers have some experiences of their giving birth that can be a base and guide for their care providers to help them more easily and effectively and these experiences and also supports should not be neglected. Then, the present study was conducted with the aim of exploring women’s personal experiences of giving birth in Gonabad city.A qualitative approach, specifically phenomenology was chosen because the purpose of the study was to explore and describe the meanings and concepts of the women’s experiences of giving birth. There are many interpretations of phenomenology and the philosophical beliefs of phenomenologists are different with each others. Since the aim of this study was to explore, describe and understand women’s experiences of giving birth, therefore the Husserlian phenomenological approach was used, because Husserl’s interest was in studying the phenomena as they are appeared through the consciousness of individuals. And also this qualitative approach was used in order to survey women’s experiences of giving birth with the aim of achieving a diverse picture of women’s experiences in giving birth. Then, 21 primiparae women with the age range of 19-29 years, who willingly took part in the study, were surveyed through in-depth interviews. Based on a purposeful sampling the interviews were continued to reach data saturation and no more necessary interviews were diagnosed. All the interviews were taped, transcribed and then analyzed by a qualitative content analysis method. The participants’ literacy and social class were excluded since their experiences of giving birth were the most intention of the study. A scientific process seems necessary to show women’s views or concepts of giving birth as they really emerge. In this study Husserl philosophic approach  was used. In fact, willingness and attitude to the reality of experience based on understanding of reality and new ways have been proposed to perform giving birth cares.Gonabad city with population over 120,000 and an area of 10,000 square kilometers is located in south of Khorasan-e-Razavi Province, 260 km far from Mashhad. It is located in east longitude of 46-57 to 27-59 and latitude of 30-34 to 34-54 . It has The study was approved by the Ethics Committee of research of Gonabad University of medical sciences. The participants were orally informed about the study. All the participants were informed of the study objectives which were women’s experiences of giving birth and the participants were taught how to perform the in-depth interviews. Before the interviews, the participants’ written informed consent was obtained. The interviews were recorded on tapes and they were assured that the information would remain confidential and anonymous and the participants were also told that they would be allowed during the interviews to cancel or leave it if they would not like to continue their interviews at any stage. The interviews were conducted in a calm and silent room that was a special place in their own choice.In the present study, unstructured interviews were used for collecting data which allowed flexibility and made it possible for the researchers to follow the interests and thoughts of the participants.nd postpartum cares about two weeks after their giving birth. Bracketing was performed by the interviewers before performing the interviews. The use of bracketing defends the validity and objectivity of interpretation against the self-interest of the researcher . Defaults or pre-assumptions of the researchers resulted from their experiences, literature and previous researches were identified and excluded and literature review was postponed until after the completion of data analysis. All the interviews were carefully listened and read several times in order to extract the meanings of the participants’ descriptions and explanations. The written interviews with the women were re-matched exactly with the recorded data on tapes. All transcripts were checked against tapes for its accuracy. The credibility, conformability, auditability, dependability and transferability of the study were conducted based on Guba and Lincoln method and procedure . It was Words and phrases were highlighted in the text. Concepts in the highlighted data were coded. These codes were compared to other codes within the same interview and with other interviews with different participants. Any similarities and differences were noted. Codes were grouped and categorized according to themes and then compared with concepts emerged from the research literature. On the other hand the concept(s) of any statement was explained and each concept was given a code, the codes were classified in categories and the same codes were put in the related categories and then the categories were compared with the original descriptions of the participants during the in-depth interviews for accreditation and conformity . Then thData analysis developed concepts and categories. Three themes or three main concepts, some constituents and sub-themes emerged from data analysis of the women’s experiences in normal giving birth. These concepts and constituents emerged from their experiences of giving birth were conceptualized. What was found and understood as a need and seemed necessary from the concepts and the participants’ statements were as the followings:This concept is broad in scale and covers a wide range of related constituents such as noise in the giving birth environment, providing privacy of women and dominant color of the environment that are components of the concept in the extracted codes. For example, one of the women told us that “Giving birth environment was very important and in an environment that noise is high and laborer hears permanent shouts of other women giving birth, her anxiety is increased”. A quiet and safe environment was the most urgent need of the most women for their relaxation, the other one mentioned. “Covering paravan and providing a private environment or private bed was necessary for the laborer, because when the environment is not quiet and people have no sense of security in their privacy, they feel embarrassed and this situation makes tolerance condition more difficult while the laborer is experiencing severe pain”, the other participant expressed. “I had the least cooperation with midwife when my environment was crowded and I lost my tolerance ability” and also unfamiliar environment with its tools was found as a factor or caused to increase the anxiety of women”, one of the other women also added: “Everything was frightening, Paints of the walls, curtains and equipments remembered us the operating room and I did not feel relax even when I had no pain”.This main concept includes two components such as support of laborer and midwife skills. The participants claimed that midwives were continually present on maternity ward and spoke in laborer language and were explaining techniques and progress of giving birth to women and this resulted in women’s peace and relaxation because of their presence in the maternity ward and they felt they were in good hands.For example one of the participants said: “In the morning shift that I was admitted, one of the midwives performed all my needs in good morality; she even explained me how to breathe when I had pain and this caused me to tolerate pain more easily”. One of the other participants said: “Some midwives were very good and skilled at their job such as: sorting our embryo heart properly, and regulating serum drops quickly or to inform doctor if a problem came, they did painless examinations very comfortably and if I asked them any questions, they answered me willingly and well”.This main concept is composed of several components such as: serum therapy, position status, pelvic examination, amniotomy and fasting. The majority of the participants discussed measures that increased their discomfort and anxiety. For example, asking one of the participants, she said: “Being in pain I liked to walk, but since I had a serum connected, I was forced to stay in bed and even I had problem for going to bathroom”. The other participant said: “As I was admitted they tore my amnion bag in an internal examination and I felt hot and fever and never felt well at all and all my clothes were wet. When I was moving, I got wet more and this caused me to stay in bed motionless, she added. “This motionlessness status was more difficult and suffering when I was in pain”. One of them claimed: “Very thirsty and hungry I was”. The other participant said:“I had no food from yesterday, I liked a little water or fruit juice to drink, but only my lips were wet with a wet gas, they were cracked”. Almost all the participants reported: Fear of pelvic examinations and discomfort resulted from it as one of the most bitter and hard experiences of themselves in giving birth”.One of the women said: “I requested C-section (Caesarean) to escape from repeated internal examinations regularly conducted by gynecologist and midwives”. One said: “If the internal examination was not performed, giving birth was easier to tolerate”. These statements contained related codes and concepts which form infrastructures of the main concept of usual care measures after data analysis. In general women’s claims and complaints showed and appeared some new points to return us back or gave us a feedback to find new ways or solving approach to overcome challenges ahead. The findings or derived results are the map of the way for all midwives or caregivers or as a mirror that shows and reflects what and where we are and help and guide us to find and reach the goal and how we should be in the future.There is limited research in this area which explores and identifies women’s experiences of giving birth. However, the pain of giving birth is recognized as a large unknown process that provokes anxiety and fear. The main theoretical idea that was obtained and emerged from this study and derived directly from the data is that: If women are able to successfully adjust to their new and often unexpected reality during giving birth, and begin to reclaim their needs and their world, then they will experience a return to their normality.However available literature related to women’s experiences of giving birth is less and often limited by its methodology, but the present study findings revealed that what experiences women obtained of giving birth phenomenon. The women, who had a giving birth, believed that providing an appropriate environment was one of the most important factors influencing the progress of giving birth. A quiet and silent environment with soft colors and preparing special environment for each woman could reduce their anxiety. In a study in accordance with the present study it was claimed that anxiety could increase secretion of catecholamine and this in turn declined oxytocin of the blood that made difficulty for the progress of giving birth . Thus, pAlso, an article entitled “The importance of privacy in labor” performed by Judith in New Jersey of America noted that in human or animals that suffered from fear, intimidation during childbirth, catecholamine’s hormone was released that could make trouble for laborer. When mental health status of women is changed, the level of blood catecholamine is increased and this slows or stops giving birth process. This research paper offers the importance of a safe and quiet environment and warns people from unnecessary interventions and demands giving confidence, internal and inherent abilities for normal giving birth. The research also has expressed that physical and mental support must be continued, and then these findings are in accordance with our study findings and approve the results. Even research on mice has shown that when they had not any safety and privacy, their giving birth was difficult. Women will be anxious in the hospitals environments whenever they are faced with the equipments, devices and unfamiliar people due to their privacy disruption and this can lead to the release of stress hormones and make some problems for giving birth process . AnotherWaldenstrom et al study “birth experience” showed that staffs, support had a positive influence on giving birth experience. Supporting during giving birth increases the success of breast-feeding and creates strong and positive relationship between mother and child and decreases the need for intervention. The study also supports continuous presence of midwives and encouraging of laborer . These fA qualitative study by Berg and colleagues entitled “a phenomenological study of women’s experience of giving birth with complications” showed that women’s true nature in encountering midwife and her support during giving birth is the presence of midwife, this means that cares should be performed by a midwife and the laborer status should be explained to her in her own language .Lundgren et al. in a study showed that the presence of midwife and her contact with laborer could help mothers to use their power and ability to deal with the symptoms resulted from their body (pain) during giving birth. Reduction of pain by drugs can never be a replace of communications, attentions and personnel support for the laborer .Another study by Dahlberg and Berg showed that women in giving birth which are faced with midwifery complications do not state or complain with length of giving birth and medical interventions, but what is a principle and important for the laborers is midwife skills and telling them the truth  because of fetal distress. So, it has been suggested that amniotomy should be done in the cases in which giving birth progress is encountered with difficulties  rate and potential risks involved that in turn it will result in good outcomes such as breast-feeding success. Feeling a sense of control over giving birth process will help women to feel positive about their experiences, even though it may differ from their expectations. The only thing that we should do is production of knowledge on health care that can be achieved through women’s experiences in a scientific method. Then, mothers should be asked how and what giving birth is and what does it mean to them? This information can help to define the roles of gynecologists and midwives as maternity care providers.If women are to be empowered by making choices for giving birth, then, it is therefore important for midwives to explore and discover the expectations and feelings of women in their care, and then to respect, support and fulfill them during giving birth. Then, these experiences may help the midwives to do their best for the mothers and babies since some birth places or settings are more appropriate and mother-friendly than others. These also are the best ways for birth assisters to be more mother-friendly in their dramatic task or job and the experiences can be useful in giving better care for the women. Positive and negative aspects of women giving birth should be considered to make suitable decision for the future.At the end, we conclude that health of mothers is health of babies and they are those who will manage our future world, and then mothers should be considered any way. Educational programs and birth preparation classes for mothers would help to reduce women’s emotional discomfort and alleviate their concern for their supporters. All mothers should have the opportunity to give birth based on their own terms in a quiet, supportive and calm environment.


We aimed to evaluate the association of birth weight SDS (BWSDS) with insulin resistance, blood pressure, and auxology in children and adolescents born 23–42 weeks of gestation.We studied 143 singleton children and adolescents aged 9.3 ± 3.3 years (range 2.0 – 17.9 years). Clinical assessments included auxology, insulin resistance measured by the HOMA2-IR, and blood pressure from sphygmomanometer measurements. Continuous associations were examined and stratified analyses carried out. For the latter, participants were divided into those of below-average birth weight  and above-average birth weight .Irrespective of gestational age, lower BWSDS was associated with progressively increased insulin resistance (p<0.0001) and fasting insulin concentrations (p<0.0001). Decreasing BWSDS was associated with higher systolic (p=0.011) and diastolic (p=0.006) blood pressure. Lower BWSDS was also associated with decreasing stature (p<0.010). The BBW group was ~40% more insulin resistant than ABW participants (p=0.004), with the former also displaying fasting insulin concentrations 37% higher (p=0.004). BBW participants were 0.34 SDS shorter than those of higher birth weight (p=0.002). On average, BBW participants failed to meet their genetic potential, tending to be shorter than their parents (p=0.065). As a result, when corrected for parents' heights, BBW participants were 0.6 SDS shorter than those born of higher birth weight (p=0.001). Sub-group analyses on participants born appropriate-for-gestational-age (n=128) showed that associations of BWSDS with both insulin resistance and stature remained .Decreasing BWSDS  is associated with adverse metabolic profile and lower stature in children and adolescents.


Background: Urachal remnants are a group of rare anatomical anomalies that include cysts, diverticula, and tumors. We present a case of a young female patient with dyspareunia and dysorgasmia related to a urachal cyst.Case: A patient with unique presentation of urachal cyst treated robotically. Patient had complete resolution of symptoms postoperatively.Conclusion: Robot-assisted excision of the urachal remnant provided durable symptom relief. While screening ultrasound studies of asymptomatic children have shown urachal remnants to be common, in practice, we only learn about the ones that become symptomatic. When a urachal remnant becomes inflamed or infected, patients will have fever, erythema, pain, hematuria, urinary retention, urinary tract infection, or an abnormal midline mass. Occasionally, patients may present with an acute abdomen or rarely dyspareunia.1TTreatment of these anomalies has typically involved removal by open or laparoscopic surgery. In the present case, we describe a young female with a urachal cyst that presented acutely with a surgical abdomen and later caused chronic intermittent lower abdominal pain, dyspareunia, and dysorgasmia. The patient was managed with robotic excision of the cyst and had subsequent resolution of her symptoms.Escherichia coli and Enterococcus faecalis. She defervesced with antibiotics and conservative measures.A 29-year-old female presented to the emergency department with severe abdominal pain. A CT scan showed a possible urachal diverticulum with signs of surrounding infection and inflammation. Her urine culture grew out Eight months later, she was referred to urology with a history of chronic suprapubic pain, dyspareunia, and dysorgasmia. The pain was described as intermittent lasting minutes to hours. She also noted soreness in the suprapubic area and bloating. Follow-up MRI revealed a benign-appearing multilocular urachal cyst with thin nonenhancing septations as depicted in The patient was positioned in the steep Trendelenburg position and an 18F three-way Foley catheter was inserted. We insufflated the abdomen supraumbilically using a Veress needle. The procedure was done transperitoneally with port placement similar to a standard robotic prostatectomy. The urachus was divided and the bladder was mobilized from the anterior abdominal wall by incising the peritoneum lateral to the medial umbilical ligaments. The space of Retzius was developed. A flexible cystoscope was placed into the bladder to illuminate the bladder dome and urachal remnant—this video feed was transmitted into the Tile Pro™ software of the robot to allow simultaneous cystoscopic visualization through the robotic console illustrated in The patient was discharged home the same day. Her catheter was removed on day 3. She has remained symptom free over the past 12 months since surgery.2Embryologically, the urachus is the remnant of the allantois, which connects the urogenital sinus (the upper portion forms the bladder) with the umbilicus. During the fifth month of development, as the bladder descends into the pelvis, it pulls the urachus down with it creating a canal. Then, the urachus normally obliterates, forming the median umbilical ligament, which lies between the transversalis fascia and the peritoneum.2 Common symptoms include clear umbilical drainage, fevers, and pain. These patients may also be picked up with an abnormal physical examination or radiologic finding. Rarely will patients develop a malignant transformation of the urachal remnant. In these rare instances, it is typically adenocarcinoma of the urachus and carries a poor prognosis.When the urachal channel persists, it can lead to a spectrum of anomalies ranging from a cyst to a sinus diverticulum or a fistulous tract. Most urachal remnants are asymptomatic and they account for about 3 in 200,000 hospital admissions. Patients usually present between the ages of 16 and 35 years.1 While the exact link between the urachal cyst and these symptoms is unknown, it is our theory that the increased abdominal pressure associated with orgasm and intercourse may lead to irritation of the chronically infected cyst. This irritation may manifest as pain and may help explain why excision of the mass led to the immediate relief of her symptoms. The constellation of symptoms in the report by Zanghi and colleagues closely mirrors those of our patient.The management is tailored according to the severity of the case. In the current case, the cyst probably became infected imitating an acute abdominal picture. After resolution of the infection, she suffered from dyspareunia and dysorgasmia likely due to smoldering chronic inflammation of the cyst. Dyspareunia appears to be a rare symptom of a urachal cyst. To our knowledge, ours is the second such report. Zanghi and colleagues discussed a 28-year-old woman with a urachal cyst causing dyspareunia and a sensation of fluid flowing in her abdomen.4 The robotic approach is unanimously considered to improve cosmesis and visualization compared with open surgery. In our case, the 3D vision and the dexterity of the robot significantly aided with the dissection of the urachal cyst and bladder reconstruction. We found that the use of a flexible cystoscope concurrently with robotic dissection of the cyst provided a valuable extra layer of real-time information; this allowed us to fully excise the cyst without having a cystotomy. Real-time cystoscopic assistance would have been particularly helpful if the mass involved the mucosa or exhibited malignant features as this would have necessitated a partial cystectomy.Symptomatic urachal cysts may initially be treated conservatively with antibiotics and require percutaneous drainage, however, they will often recur. Therefore, if symptoms persist or if malignancy is suspected, surgical excision is recommended. Open, laparoscopic, and robotic approaches have been effectively utilized. While most of the minimally invasive studies discuss a laparoscopic approach to the urachal remnant, recently, several case reports have been published using a robotic approach for the treatment of urachal remnants.There are inherent limitations to a case report. Our case illustrates effective robotic excision of a urachal cyst with complete symptom resolution. However, pain or dyspareunia alone may not be sufficient cause to warrant the risks of surgery because of the complex and often multifactorial nature of this entity. Due to the wide range of symptoms that urachal anomalies may cause, one must consider the entire clinical scenario. We therefore cannot be certain that future patients would have similar results even with similar symptomatology.This case represents a unique presentation of a chronically inflamed/infected urachal cyst with intermittent dyspareunia and dysorgasmia. The cyst was effectively treated with robotic excision and the patient had subsequent relief of her symptoms. We believe that robotic excision of urachal remnants offers similar benefits to those afforded by laparoscopic surgery, with added dexterity and visualization. The optimal management of this rare malady remains to be determined.


Low birth weight (LBW) and environmental tobacco smoke (ETS) exposure are each associated with wheezing in children. This study was designed to examine the combined association of LBW and ETS with wheezing.A retrospective birth cohort analysis linked with a national survey of allergic disorders among 1,018,031 junior high school students in Taiwan (1995–1996) was analyzed. The reported incidence of wheezing (yes or no) and ETS exposure  were obtained from validated questionnaires. Multiple logistic regression models were used to assess the associations of interest.There were 844,003 (83%) subjects analyzed after the exclusion criteria. LBW was associated with an increased risk of reporting ever wheezing , current wheezing  and wheezing with exercise  within the smoke-free cohort. Higher ETS exposure correlated to a higher risk of wheezing . With ETS exposure, adolescents from the lowest birth weight cohorts were more likely to report wheezing .ETS and LBW each has been related to increasing public health risk for respiratory symptoms among adolescents. Furthermore, LBW may aggravate the risk among those exposed to ETS. LBW, ETS and associated respiratory impairments may deserve special attention as part of a comprehensive environmental health risk assessment directed toward prevention and intervention. A number of studies have linked low birth-weight to subsequent asthma in young children  and adolMost of the effects of premature birth on children have been documented, and long-term follow-up studies on respiratory symptoms in children born at term are rare. In the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study , 3,628 cThe study was based on a retrospective cohort, which was developed by linking the results of a nationwide respiratory health survey of junior high school children to the subjects’ respective birth records obtained from the Taiwan Birth Registry. The Taiwan Birth Registry was established in 1978 to collect key birth demographics including birth date, sex, parity, gestational age, birth weight and limited parental/environmental characteristics [Of the 1,139,452 junior high school students nationwide at the time, 1,018,031 (89.3%) students aged 12–15 years submitted completed International Study of Asthma and Allergies in Childhood (ISAAC) designed questionnaires, which were subsequently validated by computerized quality control programs . This stInformation was collected regarding the current and past household smoking status of each participant’s adult household members and regular household visitors. The ETS exposure assessment was based on the question “How many cigarettes are smoked inside the house per day?” The answers included 4 categories: no smoking, 1–20, 21–40, and ≥41 cigarettes per household per day. To avoid the confounding effect of active smoking, 24,153 participants who were currently smoking were excluded.Ever wheezing, current wheezing and wheezing with exercise were identified by a positive answer to the following questions: “Has your child ever had wheezing or whistling in the chest, and shortness of breath at any time in the past?”; “Has your child had wheezing or whistling in the chest, and shortness of breath during the past 12 months?” and “Has your child’s chest sounded wheezy during or after exercise during the past 12 months?” ,12. PhysThe birth condition is based on Taiwan Birth Registry. Three birth weight groups were categorized . Two gestation age groups were also categorized (<37 weeks and ≥37 weeks). Furthermore, for birth order information, 4 groups were divided .P-values were based on two-tailed assumptions. Statistical significance was set at 0.05.Adjusted odds ratios (ORs) and 95% confidence interval (CI) were estimated by multiple logistic regression models for wheezing (yes or no) associated with birth weight, ETS and potential risk factors . Further joint effects of birth weight and ETS regarding adolescent wheezing were assessed after adjusting for potential risk factors. A sensitivity analysis was conducted for adolescents without physician-diagnosed asthma or rhinitis. SAS software, version 9.3, was used in the analysis . All of the reported There were 844,003 surveys available for the current analyses after the exclusion criteria were applied Figure . The ratAs compared with normal birth weight (2500–4000 g), LBW was associated with an increased risk of having ever wheezed , current wheezing  and wheezing with exercise . ETS exposure was progressively associated with higher adjusted ORs for symptoms of wheezing. For the highest ETS exposure group, the increased risk was as follows: having ever wheezed , current wheezing  and wheezing with exercise  , current wheezing  and wheezing with exercise . Furthermore, those in the LBW cohort had the highest risk of ETS exposure related ever wheezing , current wheezing  and wheezing with exercise   responses. The combined sensitization to allergens and added effect of ETS on Th2 responses may have been responsible for the prevalence of allergic symptoms in individuals with tobacco smoke exposure. Tobacco smoke can worsen atopic conditions by irritating the skin and mucous membranes, thus facilitating the access of allergens and the opportunity for sensitization .Furthermore, oxidative stress associated with the exposure to cigarette smoke could act epigenetically via pro-inflammatory genes by altering transcription factors  and histones or by remodeling chromatin. In children born at LBW, cigarette smoke could contribute to reduced histone deacetylase activity. Reductions in this key transcriptional moderator can favor the activation of NF-κB and the expression of the proinflammatory cytokines IL-6 and IL-8 in susceptible immature lung tissue, which may later lead to the development of asthma .Whether the increased vulnerability associated with LBW is the result of subtle changes in prenatal programming or the reactive adjustments of less immunologically mature infants to the post-natal environment is unclear. Although understanding the cause will obviously facilitate the finding of an appropriate remedy, it is very clear that children with LBW should be carefully monitored for early signs of wheezing and allergic disorders. Despite these caveats, it is abundantly clear that exposure to ETS is a significant threat to the health of all children.The strength of the current study is derived from its large, representative national sample, which should provide an unbiased estimation of risk. The study is the first to address the joint effects between birth weight, ETS and wheezing symptoms . Increasing ETS exposure was a factor in the expression of wheezing symptoms, especially in subjects with LBW. Consistent dose–response effects were observed.Maternal smoking but not paternal smoking during pregnancy was related to LBW and preterm delivery . MaternaThere were several potential limitations in the analysis. Wheezing symptoms and ETS were estimated cross-sectionally, and no specific prenatal, during pregnancy or perinatal ETS exposure data were available. The cross-sectional study provided little information about the causal relationship between ETS and wheezing symptoms. Prenatal maternal smoking  has been proposed as a contributing factor to LBW ,19-21. LIn summary, this study provides an unbiased estimate association within a large national sample. An increased risk of wheezing is related to LBW children. A significant dose–response association between ETS exposure and the rate of wheezing was clearly demonstrated. LBW and ETS exposure could have significant independent and joint effects on respiratory health in smoking-free adolescents. We recommend that adolescents should avoid ETS exposure to reduce the risk of wheezing, especially for those born with LBW.LBW: Low birth weight; ETS: Environmental tobacco smoke; OR: Odds ratio; CI: Confidence interval.The authors declare that they have no competing interests.WCH, PCC, TNW, RSL: conception and survey design. MHL, JCL, YSL, CCL: conducted the statistical analyses. MHL, WCH, JLC, YSL: interpretation of the data, drafting the manuscript. All authors contributed to the, revised the article critically for important intellectual content, and approved the final manuscript. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2458/14/688/prepub


Early studies have suggested that biomass cooking fuels were associated with increased risk of low birth weight (LBW). However it is unclear if this reduced birth weight was due to prematurity or intrauterine growth restriction (IUGR).In order to understand the relationship between various cooking fuels and risk of LBW and small for gestational age (SGA), we analyzed data from a birth cohort study conducted in Lanzhou, China which included 9,895 singleton live births.Compared to mothers using gas as cooking fuel, significant reductions in birth weight were observed for mothers using coal  and biomass . Using biomass as cooking fuel was associated with more than two-fold increased risk of LBW , and the risk was mainly seen among preterm births . No significant associations with LBW were observed among mothers using coal or electromagnetic stoves for cooking.These findings suggest that exposure to biomass during pregnancy is associated with risk of LBW, and the effect of biomass on LBW may be primarily due to prematurity rather than IUGR. Low birth weight  is an important indirect cause of infant death worldwide  and moreStudies have linked LBW with certain environmental factors, such as maternal smoking and ambient air pollution , 35, 38.n = 323), stillbirths (n = 40), birth defects (n = 253), births with missing information on birth weight (n = 30), and gestational age <22 weeks (n = 1), the analytic sample size was 9,895.The present study was based on data from a birth cohort study conducted during 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital (GPMCCH), the largest maternity and childcare hospital in Lanzhou, China . A totalEligible women were informed of the study procedure upon their arrival at the hospital for delivery. After obtaining written consent, an in-person interview was conducted at the hospital either before or after delivery by trained study interviewers using a standardized and structured questionnaire. The questionnaire collected information regarding demographic factors, reproductive history, medical conditions and medication use, occupational exposures, and residential history.Each participant was asked about current and past residences throughout her lifetime, including length of time residing at each residence (measured by dates of move-in and move-out). For each current and past residence, participants were asked about type of cooking fuel utilized , ventilation practices while cooking, most frequently used types of cooking oil , and the most commonly used cooking method .Information on birth outcomes and pregnancy complications were abstracted from medical records. Birth weight was measured in grams by trained professional nurses within the first hour of life. According to World Health Organization, LBW is defined as birth weight <2,500 grams, normal birth weight (NBW) is defined as birth weight between 2,500 grams and <4,000 grams, and macrosomia is defined as birth weight ≥4,000 grams .n = 17), a United States national reference was applied for those with gestational ages between 22 and 27 weeks [Gestational age was calculated in completed pregnancy weeks based on the date of the last menstrual period. Information on last menstrual period was extracted from medical records. All self-reported last menstrual period dates were further verified by ultrasound examinations during antenatal care in the hospital. SGA, a measure of IUGR, is defined as a specified birth weight below the 10th percentile for gestational age of a reference standard; appropriate for gestational age (AGA) and large for gestational age (LGA) are specified as birth weights between the 10th and 90th and greater than 90th percentiles, respectively, for gestational age of the same reference standard . We cons27 weeks .Chi-square or Fisher exact tests were employed to compare selected characteristics between LBW and NBW and between SGA and AGA. ANOVA tests were utilized to compare infants’ mean birth weights among women who utilized various types of cooking fuel during pregnancy. Unconditional logistic regression models were used to examine associations between cooking fuel and LBW and SGA. Potential confounding factors including maternal age, education, family income, parity, maternal weight gain during pregnancy, caesarean section, preeclampsia, vitamin supplements during pregnancy, smoking (active and passive), ventilation while cooking, and gestational age were included in the final models. Additional adjustment for maternal pre-pregnancy body mass index (BMI), alcohol consumption during pregnancy, gestational diabetes, infant gender, cooking temperature, and cooking oil type did not result in material changes in the observed associations and thus were not included in the final models. Odds ratios (OR) and 95 % confidence intervals (CI) were calculated using an unconditional logistic regression model. All analyses were performed using SAS 9.3 version .2) compared to women with AGA infants.In our cohort, 650 births were LBW and 8,581 were NBW while 746 births were SGA and 7,775 were AGA  for cooking. A total of 140 participants used electromagnetic stoves and other stoves simultaneously, which accounted for approximately 22.3 % of women who ever used electromagnetic stoves. Women who used coal, biomass, or electromagnetic stoves were younger and less educated, and had lower family income and vitamin supplementation intake compared to women who used gas stoves. They were also more likely to be multiparous, have higher BMI, be diagnosed with preeclampsia, and report exposure to tobacco smoke during pregnancy. Women who used coal or biomass were more likely to have a higher caesarean section rate as compared to those who used gas. Infants delivered by women who used coal, biomass, or electromagnetic stoves were more likely to be LBW or SGA. Women who used coal, biomass, or electromagnetic stoves were also more likely to report poor cooking ventilation compared to those who used gas stoves.In our study population, 7,907 participants exclusively used gas as their cooking fuel, 358 exclusively used coal, 120 exclusively used biomas, and 487 exclusively used electromagnetic stoves (Table Table The association between the various cooking fuels and LBW is presented in Table n = 11 exposed cases).In our study population, 910 (9.2 %) infants were preterm, with a mean gestational age of 33.8 (SD = 2.3) weeks. Among the preterm births, 776 were moderate to late preterm births  and 134 were very preterm births . We stratified the analysis by preterm and term births Table . A signiWe further analyzed the association between cooking fuel types and the risk of SGA Table . CompareThis study is the first to investigate the associations between various types of cooking fuels and risk of LBW and SGA in the Chinese population. Our results support the hypothesis that use of biomass for cooking is associated with an increased risk of LBW compared to use of gas, and suggest that the association between biomass and LBW is likely due to prematurity but not IUGR.Our study population primarily resided in an urban area. We noted a relatively high prevalence of gas stove use and low prevalence of biomass use compared to what we might expect in rural areas. The unbalanced prevalence of exposure may impact the accuracy of model estimation. However, the observed increased risk of LBW associated with biomass use was consistent with previous epidemiologic studies , 34, 36.All of these published studies were conducted in areas where there was a very high prevalence of LBW, with rates as high as 33 %. In addition, the percentage of households that used biomass as a primary fuel source was also very high (up to 79 %), suggesting that the study populations had a very low socioeconomic status (SES). Malnutrition, which is common in these areas, plays an essential role in birth weight particularly in IUGR. However, neither these important confounders nor gestational age were controlled for in these prior studies.2), sulfur dioxide (SO2), and polycyclic aromatic hydrocarbons (PAHs) [2 content of maternal blood is reduced. Subsequently, O2 delivery to placenta is reduced, resulting in preterm delivery and subsequently LBW. Both epidemiological [Increased risk of LBW associated with biomass has been consistently reported in the literature, supporting our findings. Combustion of biomass fuel emits high concentrations of airborne particulate matter (PM) and toxic chemicals including carbon monoxide (CO), nitrogen dioxide (NOs (PAHs) , 42. Wheological , 35, 38 ological  have linOur study found that the effect of biomass on LBW was attenuated after adjusting for gestational age, which indicated a negative confounding effect. After stratification by preterm and term births, a significant association with biomass was only observed among preterm births but not term births. Our study also found no significant association between biomass and SGA, consistent with results from a recent study in India . All theThe literature has described a rapid rise in caesarean sections in China in the past decades. The current national rate is nearly 40 %, irrespective of geographic location or SES . In our A study from India reported a significant association between LBW and using coal for cooking, though they did not adjust for gestational age . This waWe found that electromagnetic stoves were not associated with an increased risk of either LBW or SGA after controlling for gestational age. Electromagnetic stoves, more commonly known as induction cookers, use the electromagnetic induction principle to heat and cook food. Because the electromagnetic stove has many attractive features such as high energy efficiency, low noise, and no open flame, more families are beginning to replace coal, biomass, and gas stoves with induction stoves. To our knowledge, no previous study examined the association between electromagnetic stoves and LBW and SGA. Several studies have examined the association between electromagnetic fields (EMFs) and fetal growth. However, the results were inconsistent . OccupatThe study population was recruited from the largest maternity and child care hospital in Lanzhou, the capital city of Gansu Province. The majority of study population came from Lanzhou City. Approximately 20 % of the remaining study population came from other cities and towns in Gansu Province. Although the study was hospital-based, which might impact generalizability, the LBW rate (6.2 %) in our study population was similar to the previously reported LBW rate (5.0 %) in all of Gansu Province .Strengths and limitations should be considered when interpreting the study results. Information on birth weight was obtained from medical records and birth weight was measured in grams by trained professional nurses within the first hour of life, minimizing potential misclassification of the outcome. Information on gestational age was available, which allowed us to not only control for gestational age when studying the relationship with LBW, but also examine the association with SGA. One concern is that information on household heating source was not collected in the study. Since the majority of the study population came from urban areas where heating was centralized, the number of households using other fuels  for heating was expected to be minimal. Generally households using coal or biomass for heating were likely to have lower SES; therefore we adjusted for SES (using education and family income as proxies) in our models. Lack of information regarding whether study participants were the primary person in charge of food preparation, number of meals cooked per day, and time spent in the kitchen might result in exposure misclassification. However exposure misclassification would likely be non-differential, if any, resulting in an underestimation of the observed associations. Given the various sources and factors that might influence indoor air pollution, it is important for future studies to employ more accurate methods, such as household or portable air quality monitors, to assess indoor air pollutants exposure.Our findings provided further support for the hypothesis that exposure to biomass is associated with an increased risk of LBW. Our study suggests that the effect of biomass smoke on LBW could be primarily due to prematurity rather than IUGR. Future studies are needed to clarify the biological mechanisms underlying the association. Additionally, a suggestive association between induction stove use and SGA warrants further investigation.