We have found that few attempts are reported on Williamson fluid flow yields by an inclined cylindrical surface. To be more specific, Williamson fluid flow regime characteristics under stagnation point region especially when it is manifested with mutual interaction of double stratification and mixed convection effects are not proposed as yet. Therefore, we have considered stagnation point mixed convection Williamson fluid flow brought by an inclined cylinder in the presence of temperature and concentration stratification phenomena. Further, the fluid flow is entertained through no slip condition i-e the velocity of particles is directly related to velocity of cylindrical surface due to stretching. The physical situation within the real concerned constraints is translated in terms of differential equations as a boundary value problem. To make implementation of computational algorithm possible, following steps are taken into account•The PDE’s are transformed into ODE’s by using suitable transformation.•The resulting boundary value problem is converted into an initial value problem.•These constructed ordinary differential equations are solved computationally by shooting technique charted with Runge-Kutta scheme.•The effect logs of an involved physical flow parameters are explored by way of graphical outcomes and tabular values. The study of non-Newtonian fluids flow brought by stretching surfaces is always remains a topic of great interest and has received outstanding attention by the researchers due to their numerous applications in an industrial and engineering process. To be more specific, pulps, sugar solutions, tomato ketchup, and shampoos are the well-known examples of non-Newtonian fluids. In non-Newtonian fluids, there exists non-linear bond between deformation rate and shear stresses so, it is difficult to narrate the accurate salient features of non-Newtonian fluid models. To clip out the complete description of non-Newtonian fluids flow different model are proposed by scientists like Maxwell fluid model (1867), Barus fluid model (1893), Bingham Herschel-Bulkly (1922), Ostwald-de Waele power law model (1923), Williamson fluid model (1929), Eyring fluid model (1936), Burgers fluid model (1939), Generalized Burgers (1939), Reiner-Rivlin fluid model (1945), Oldroyd-A (1950), Oldroyd-B fluid model (1950), Oldroyd-8 constants (1950), Glen fluid model (1955), Rivlin-Ericksen (1955), Criminale-Ericksen-Filbey (1957), Sisko fluid model (1958), Kaye-Bernstein-Kearsley-Zapas , Seely fluid model (1964), Cross fluid model (1965), FENE-P (1966), Carreau fluid model (1972), Carreau-Yasuda fluid model (1972), Johnson-Segalman fluid model (1977), Johnson-Tevaarwerk (1977), Phan-Thien-Tanner fluid model (1978), Giesekus fluid model (1982), FENE-CR (1988), Ellis fluid model, Blatter fluid model (1995), and White-Metzner, Rolie-Poly. In short, the interest of researchers and scientists immensely increased towards rheological features of non-Newtonian fluids like Abel et al. To be more specific, out of these non-Newtonian fluid models, Williamson model is quoted as fluid with pseudo-plastic features. In addition, Williamson fluid model admits shear thinning properties. The industrial and biological liquids that obey the Williamson fluid are polymers, melts/solution, ketchup blood, paint, and whipped cream to mention just a few. Williamson The assessed literature survey reflects that an investigation subject to Williamson fluid flow brought by an inclined stretching cylindrical surface manifested with double stratification is not reported as yet. Therefore, the key aim of present attempt is to inspect the influence of double stratification effects along with mixed convection on Williamson fluid flow under stagnation point region carried by an inclined stretching cylinder. To the best of our knowledge it seems to be a first attempt in this direction to discuss the double stratification effects on Williamson fluid flow along an inclined stretching cylinder under stagnation point region in the presence of mixed convection effects. For this purpose both temperature and concentration are taken as variable quantities at the cylindrical surface and away from it. The flow field situation is translated in terms of boundary value problem and the numerical simulation is carried out for their solution. Further, the effect logs of an involved physical flow parameters are explored through graphs and tables.We have considered steady an incompressible and two dimensional mixed convection boundary layer stagnation point flow of non-Newtonian fluid model (Williamson fluid) brought by an inclined stretching cylinder. Flow situation is accounted with temperature and concentration stratification. The temperature as well as concentration at the surface of cylinder are assumed be higher in strength as compared to ambient temperature and concentration respectively. The boundary layer approximation reduces the flow controlling differential equations to forms given as follow:x-axis and r-axis is perpendicular to it. The velocity components u is in the x direction while v in the r direction. Whereas, ν, ρ, g, σ, Tβ, Cβ, α denotes kinematic viscosity, fluid density, gravity, electrical conductivity, coefficient of thermal expansion, coefficient of concentration expansion and an inclination of cylinder with x-axis respectively. Whereas, κ, pc, and D, denotes thermal conductivity, specific heat at constant pressure and mass diffusivity respectively. The corresponding boundary conditions of problem are given by:the axial axis of cylinder is supposed as wT(x), wC(x), ∞T(x), ∞C(x), T0, C0 denotes prescribed surface temperature, surface concentration, variable ambient temperature, variable ambient concentration, reference temperature and reference concentration respectively, where b, c, d and e are positive constants. Where, ψ is the stream function, which identically satisfies the continuity Eq. where, U0 is the free stream velocity, L is the reference length, f(η) represents dimensionless variable so that, f' (η) is the velocity of fluid over an inclined stretching cylinder having radius R. In the field of fluid mechanics for particular problem a distinct set of similarity transformation may exist and can be obtained by using Lie group analysis. In addition, the boundary layer problems inherit some type of scaling symmetry due to the Buckingham Pi theorem To trace out the solution of Eqs. Once incorporating Eqs. K, λ, mλ, N, α, Pr, β1, β2, A and Sc denotes curvature parameter, Weissenberg number, mixed convection parameter, ratio of concentration to thermal buoyancy forces, Prandtl number, thermal stratification parameter, solutal stratification parameter, velocities ratio parameter and Schmidt number respectively and given as follow:Gr and Gr* denotes Grashof number due to temperature and concentration respectively and defined as:the reduced boundary conditions are:μ denotes viscosity of fluid and wτ is the shear stress. The dimensionless form of skin friction coefficient is given byThe skin friction coefficient is considered at the surface of cylinder and given as:with The local Nusselt and Sherwood numbers are defined as:in dimensionless form, these quantities can be defined as:The Eqs. then the equivalent form of Eqs. the corresponding boundary conditions in new variables are given as follows:In order to integrate Eq. By choosing favourable guessed values of m = 0, the current reduced to study reported by both A < 1, in other words when stretching velocity exceeds against free stream velocity. Physically, the boundary layer thickness increases largely when stretching velocity is dominant as compared to free stream velocity. Further, the involvement of free stream velocity is little significant but lesser then stretching velocity so that the particle disturbance is significant at cylindrical surface as compared to far away from surface. In A > 1. In this case free stream velocity exceeds stretching velocity. The thickness of boundary layer decreases when A increases. In actual when A increases, we yields increase in free stream velocity for fixed values of stretching velocity, ultimately straining motion adjacent to the stagnation region brings an inciting acceleration of free stream as a result thinning of boundary layer is observed.x-axis the effect of gravity reduces as a result velocity profile decreases with in boundary layer. The effect of mixed convention parameter over velocity profile is shown in x-axis the effect of gravity reduces which brings decline in temperature profile. •The compatibility of endpoint conditions is validated by providing stream lines pattern see  towards •The fluid velocity shows an inciting nature for positive value of mixed convection parameter and curvature parameter but it shows opposite trends for the thermal stratification parameter, an inclination and Weissenberg number.•The fluid temperature reflects higher attitude towards curvature parameter, an inclination and ratio of buoyancy forces but an inverse attribute is found for both thermal stratification parameter and Prandtl number.•The fluid concentration profile decreases for higher values of both solutal stratification parameter and Schmidt number.•It is noticed that the skin friction coefficient shows an inciting nature for thermal stratification parameter, solutal stratification parameter, curvature parameter, Prandtl number and Schmidt number but it shows decline nature towards Weissenberg number.•The heat transfer rate  increases for higher values of curvature parameter, Prandtl number and thermal stratification parameter.•The mass transfer rate  shows an inciting behaviour for curvature parameter, Schmidt number and solutal stratification parameter.A double stratified mixed convection stagnation point boundary layer flow of Williamson fluid flow is considered towards an inclined stretching cylinder. The flow field is translated in terms of partial differential equations. These partial differential equations are converted into ordinary differential equations. A numerical algorithm is executed to obtain concerned results and the effects of pertinent flow controlling parameters on dimensionless velocity, temperature and concentration are offered with the aid of graphs. The key results are listed as follow:


The goal of this study was to apply the varicella zoster virus (VZV) vaccine to patients with pediatric rheumatic diseases (PRD) at risk for severe chickenpox, without interrupting their current immunosuppression, including biological agents, using an immunological-based pre-vaccination checklist to assure safety. A pre-vaccination checklist was implemented to ensure adequate immune competence prior to immunization.3, lymphocytes ≥1200/mm3, serum IgG ≥500 mg/dl, IgM ≥20 mg/dl, tetanus toxoid antibody ≥0.1 IU/ml. In case of HIIS additional specifications included a CD4+ lymphocyte count ≥200/mm3 and a positive T-cell function  indicating mitogen-induced T cell proliferation). Patients who met the criteria of the pre-vaccination checklist received the first and/or second VZV vaccination. Immunologic response and side effects were monitored.This prospective study included seronegative patients (VZV-IgG ≤200 mIU/ml) and patients who had previously received only a single dose of VZV vaccine. All vaccinees demonstrated clinically inactive PRD. Patients were categorized according to their actual treatment in low-intensity IS (LIIS) and high-intensity IS (HIIS) including biological therapy. The pre-vaccination checklist defined thresholds for the following basic laboratory tests: white blood cell count ≥3000/mmn=9) and HIIS (n=14) groups. In total, 21 patients (91%) showed a positive vaccination response, after the first immunization the median VZV-IgG across all patients was 224 (59-1219) mIU/ml (median (range)), after booster immunization it increased to 882 (30-4685) mIU/ml. Two patients in the HIIS group failed to raise positive VZV-IgG, despite booster immunization. All nine patients receiving only the second immunization on IS reached high titers of VZV-IgG >500 mIU/ml (1117 (513-4685) mIU/ml). There were no cases of rash or other vaccine-induced varicella disease symptoms and no evidence of PRD flare.Twenty-three patients were recruited of whom nine had already received one VZV immunization before initiating IS. All patients met the pre-vaccination checklist criteria despite ongoing IS. There was no overall difference in VZV-IgG levels when comparing the LIIS  contains supplementary material, which is available to authorized users. Immunosuppressed individuals are at substantial risk for severe disease courses . Therefoobserved , 12. In observed , 10, 13.observed –16. Chilobserved .The current recommendations for vaccination of children with rheumatic disease by the European League Against Rheumatism (EULAR) state not to administer live-virus vaccines to patients on therapy with high-dose disease-modifying antirheumatic drugs (DMARD), high-dose glucocorticoids or biological agents except on a case-to case basis . HoweverThe goal of this study was to apply the VZV vaccine to patients with PRD at risk for severe chickenpox, without interrupting their current IS, including biological agents, using an immunological-based pre-vaccination checklist to assure safety. The checklist contained only easy-to-obtain clinical and immunologic parameters and could be used for the whole spectrum of currently used/ standard IS. This new approach is based on immunologic function rather than on type of medications. Patients demonstrating immunoreactivity despite IS received live vaccine and safety and immunogenicity data were obtained.A prospective single-center study was conducted at the German Center for Pediatric and Adolescent Rheumatology, Garmisch-Partenkirchen . The study was approved by the Institutional Board of Ethics in Medical Research of the Bavarian Chamber of Physicians. Written informed consent was obtained from all parents and the patients. Within the inclusion period from April 2012 to Mai 2013, 2802 patients between the ages of 2 to 17 years were screened by reviewing their immunization records, a questionnaire asking about prior chickenpox or herpes zoster and, in case of absence of chickenpox, herpes zoster and vaccination, by VZV-IgG screening. Inclusion criteria for the intervention part of the study were: (1) negative medical history for chickenpox and herpes zoster, (2) ≤ 1 prior dose of the VZV vaccine, (3) in case of first VZV vaccination, laboratory evidence of susceptibility for chickenpox defined as VZV-IgG either classified as negative (<160 mIU/ml) or equivocal (160-200 mIU/ml)  calibrated based on WHO reference preparation allowing quantitative measurements), (4) diagnosis of an inflammatory PRD, (5) clinically inactive disease as defined by the American College of Rheumatology (ACR) criteria in case of JIA  or a phy2/week or max. 15mg/week, (2) prednisolone (PDN) ≤0.5mg/kg/day (max. 10 mg/day) or (3) azathioprine (AZA) ≤2mg/kg/day (max. 100mg/day).LIIS included: (1) methotrexate (MTX) ≤15mg/m2/week or >15mg/week, (2) PDN >0.5 to <2mg/kg/day or >10 to <20mg/day, (3) AZA >2 to 3mg/kg/day, (4) leflunomide ≤0,5mg/kg/days or ≤20mg/day, (5) cyclosporine A ≤ 3mg/kg/day with trough level ≤100μg/l, (6) tacrolimus and mTOR inhibitors with trough level ≤4ng/ml, (7) mycophenolate mofetil (MMF) ≤1200mg/m2/day or up to 2g/day, (7) etanercept ≤0.8mg/kg/week or up to 50mg/week, (8) adalimumab ≤24mg/m2 or up to 40mg every 2 weeks, (9) infliximab ≤6mg/kg up to every 4 weeks, (10) tocilizumab ≤12mg/kg up to every 2 weeks (if body weight ≤30kg) or ≤8mg/kg up to every 2 weeks if body weight ≥30kg, (11) anakinra ≤3mg/kg/day up to 150mg/day, and (12) abatacept ≤10mg/kg every 4 weeks. Combination therapy was allowed except for combination of two biologic DMARDs.HIIS included: (1) MTX >15mg/mAfter consultation with the German Standing Committee on Vaccination (STIKO), we graded the intensity of the IS by applying laboratory testing to determine the current immunologic reactivity that should allow control of the OKA vaccine strain. Definitions regarding the level of IS were based on available recommendations , 19. Med3, lymphocytes ≥1200/mm3, serum IgG ≥500 mg/dl, IgM ≥20 mg/dl, tetanus toxoid antibody ≥0.1 IU/ml [3 if age >5 years or ≥500/mm3 if age 2-5 years) and a positive T cell function test (CMI). As an easy-to-obtain T cell function test we used a commercial interferon-gamma release assay (IGRA), the TB-EliSpot® test, which contains a mitogen as positive control (phytohemagglutinin). Patients exceeding the respective cut-off levels had adequate immunologic reactivity for the purpose of this study and VZV vaccination was offered.A checklist was developed, consisting of items regarding medical history, physical examination, contraindications, grading the level of IS and basic laboratory examinations for all patients Table . Basic l3 and/or adequate CMI). Varilrix® contains the live attenuated Oka strain at a concentration of at least 103.3 plaque-forming units per 0.5ml. Participants received a standard dose of the vaccine 0.5ml subcutaneously. A second dose was given at an interval of at least 6 weeks on LIIS and 3 months on HIIS [Patients stratified to fullfill the pre-vaccination criteria, also met the immunological precautions requested by the manufacturer of Varilrix® (Glaxo-Smith-Kline) for the in-label application of the VZV vaccine on IS  to determine if post-vaccination contact to VZV and/or breakthrough chickenpox or HZ had occurred.Statistical analysis was performed using GraphPad Prism 6  and Microsoft Excel 2010 . Demographic and baseline laboratory characteristics were described using medians and range. Differences between patients receiving LIIS and those receiving HIIS were estimated with the chi-squared test for proportions and with the Mann-Whitney test for interval variables.Within a period of 13 months 2802 patients with PRD were screened for their VZV-susceptibility by a questionnaire. Sixty patients (2.1%) reported a history of chickenpox while 2580 patients (92.1%) had received two doses of the VZV vaccine as recommended in Germany by the STIKO. Of the remaining 162 patients  potentially susceptible for VZV, 116 had clinically active PRD and 46 had clinically inactive disease. Of 46 patients with clinically inactive disease, 11 refused further study participation. Of the 35 potentially VZV susceptible patients willing to further participate in the study, 12 had a VZV-IgG >200 IU/ml indicating prior contact to VZV. Additionally, we observed titers classified as negative (<160 mIU/ml) in 4 out of 9 patients that had received a single VZV vaccination prior to the study . Twenty-three patients entered the interventional part of this study . Of the 15 patients naïve for VZV, six only received one vaccination  while nine received two . Among the six patients who received only one vaccination, one patient refused a second vaccination, and five patients  deferred a second vaccination due to an increase in VZV-IgG-level after just one vaccination. We suggested to repeat VZV-IgG level measurements in these instances and to offer the booster vaccine in case of a negative or borderline VZV-IgG level.p=0.67 after first vaccination, p=0.26 after second vaccination). Similarly, the absolute (Δ) and the relative (fold-) increase in VZV-IgG after first to after second vaccination  were not significantly different between these groups . Among participants only receiving a booster vaccination, all achieved VZV-IgG levels >500 mIU/ml, i.e. 1117 (513-4685) mIU/ml. Two participants in the HIIS group did not achieve an increase in VZV-IgG >200 mIU/ml despite two vaccinations. Patient 1 (on MMF monotherapy) and patient 2 (on leflunomide and abatacept therapy) both had VZV-IgG ELISA values in the negative range of the assays.Among patients who had received a single dose of the VZV vaccine before start of IS, the VZV-IgG baseline levels were 230 (57-1003) mIU/ml (median (range)). Figure The VZV vaccinations were generally well tolerated. There were only minor adverse events, Table After a median follow-up of three years, no patient had suffered from breakthrough chickenpox or from HZ. A known exposure to VZV was documented in three cases (one to herpes zoster and two to chickenpox).To our knowledge, this is the first study employing a pre-vaccination stratifying algorithm centered on immunologic criteria, rather than on type of IS medication used, to decide whether a IS patient got vaccinated.The implementation of the pre-vaccination checklist ensured immune competence prior to vaccination. On that basis we demonstrate the safety and immunogenicity of VZV vaccination in an insufficiently protected cohort of patients with PRD receiving LIIS or HIIS, including biologic DMARDs.All patients receiving LIIS and/or only a booster vaccination developed an increase in VZV-IgG above 200 mIU/ml (defined as positive by the manufacturer of the assay). Two out of 14 patients receiving HIIS did not: one on MMF (which has anti-proliferative activity in B- and T-cells) and one on leflunomide and abatacept (an agent blocking T cell co-stimulation). Abatacept and MMF have previously been associated with poor responses to non-live vaccine immunization –23. Our phytohemagglutinin, PHA) as positive control.For the two-step checklist, we selected parameters regarding humoral and cellular immunity that in previous studies indicated the ability to control the standard-dose Oka virus strain of the VZV vaccine even during severe IS –29. We eIn our opinion, the decision to administer both (first and booster) live vaccination might be better based on the actual immunoreactivity rather than on the type of IS medication.The alternative is to delay the initiation of IS, use a low-dose glucocorticoid bridging therapy or interrupt IS for several weeks , 27. In In 2009, Germany initiated a general 2-dose VZV vaccine schedule for healthy children receiving the first dose between the age of 11 to 14 months and the second dose between the age of 15 to 23 months , 31. GenIn countries with targeted immunization strategies the pre-vaccination checklist may be even more helpful protecting susceptible patients with urgent need for IS and high risk of chickenpox exposure. In patients without a 2-dose VZV vaccination and uncertain history of VZV disease, testing for VZV-IgG seems advisable prior to long-term IS, and negative or borderline VZV-IgG levels should lead to vaccination. On the other hand, post-exposure prophylaxis with acyclovir and VZV hyperimmune globulin may fail in preventing varicella disease during IS , 37–39. One limitation of our study is that this is a rather small cohort of patients treated with various combinations of IS. We only documented an increase in VZV-IgG but CMI may be just as important. Long-term data for VZV-IgG and cell-mediated immunity (CMI) in patients with leukemia or immunosuppression (IS) who received two doses of the VZV vaccine showed that VZV-IgG peaks and then declines over time, whereas long-lasting VZV-CMI persists and protects between 75-100% of vaccinees from clinically relevant VZV disease after exposure , 44, 45.It is noteworthy that none of the screened patients “failed” the stratification process. Based on further experience and data the pre-vaccination checklist may be simplified in the future, especially concerning booster-live vaccinations. Moreover, the application of the pre-vaccination checklist for first measles-mumps-rubella (MMR) vaccination on LIIS and booster MMR vaccination on LIIS and HIIS should be discussed. Two minor modifications have been proposed by experts regarding the application of the MMR vaccine: first, proof of an increase in antibody titer following “diagnostic immunization” with inactivated vaccines and, second, a higher threshold for CD4 + T cells (>500/μl) .In summary, we demonstrated that the monovalent VZV vaccine was well-tolerated and mostly efficacious in a cohort of VZV-susceptible patients with PRD receiving ongoing IS (including biologic DMARDs) after proving immunologic reactivity by means of a simple checklist. We believe that the safety and efficacy of this easy-to-obtain approach should be prospectively evaluated in a larger patient cohort.Additional file 1: List of 45 countries with mandatory varicella zoster virus vaccination  retrieved from the WHO vaccine-preventable diseases monitoring system 2017*. (DOCX 19 kb)


Many patients experience local recurrence or metastases after receiving potentially curative treatment, and early detection of these events is important for disease control. Recent technological advances make it possible to use blood plasma containing circulating cell-free tumour DNA (ctDNA) as a liquid biopsy. In this case report we show how serial liquid biopsies can be used to monitor the disease course and detect disease recurrence in a sarcoma patient.KRAS and NF1, were identified in the primary tumour. Targeted resequencing of plasma cell-free DNA (ctDNA) collected before and after surgery and at disease progression confirmed the presence of six of eight mutations at all three time points. The ctDNA level, estimated from the somatic allele frequencies of these six mutations, was high in plasma taken at the time of surgery, at levels similar to the primary tumour. Detection of low levels of ctDNA three days after surgery indicated persistent microscopic disease. Repeated radiologic imaging six weeks postoperatively showed widespread metastatic disease in the lungs, skeleton and the pelvic region. At this time point there was a dramatic increase in the ctDNA level, reflecting the disease progression of the patient. The patient had an unusually aggressive cancer, and succumbed to the disease 13 weeks after surgery.A 55-year-old male presented with a rapidly growing, painful palpable mass in the left groin region, and a biopsy revealed a high-grade malignant spindle cell sarcoma. No metastases were detected on radiologic imaging scans. Using targeted resequencing with a custom 900 cancer gene panel, eight somatic mutations among them This case report demonstrated that targeted resequencing of ctDNA from longitudinal collected plasma can be used to monitor disease progression in a soft tissue sarcoma patient, including manifestation of metastatic disease. The ctDNA represented the genomic profile of the tumour, supporting clinical use of liquid biopsies to identify tumour-specific mutations as well as recurrent disease.The online version of this article (doi:10.1186/s12885-016-2992-8) contains supplementary material, which is available to authorized users. Cancers arise through a sequential alteration of the genome, resulting in a heterogeneous tumour that continuously evolves as the disease progress. Material for diagnostic examination of solid tumours is routinely obtained through fine-needle biopsies. This procedure gives limited amount of material, and only provides a single snap-shot of the genetic alterations in a restricted part of the tumour. After treatment with curative intent, radiological imaging of patients to monitor local or distant recurrences is not done on a routine basis, and imaging methods also have limited sensitivity to detect micrometastases.Recent advances make it possible to use blood plasma as a liquid biopsy, examining the circulating cell-free DNA (cfDNA) shed from both normal and tumour cells into peripheral blood –3. The cSeveral reports have demonstrated that high-throughput sequencing of cfDNA may be used for prognosis and molecular stratification, early detection of recurrence and metastasis, monitoring response to treatment and identification of resistance mechanisms . SequencSarcomas make up a heterogeneous group of malignant tumours of mainly mesenchymal origin. The overall five-year survival of all soft tissue sarcoma patients is approximately 70% , 11, andAs part of an ongoing prospective study (CircSarc), we collected primary tumour and plasma samples taken before and after surgery and at disease progression from a soft tissue sarcoma patient. Targeted resequencing was used to identify somatic mutations in the primary tumour and monitor the level of ctDNA from plasma samples during the course of the disease.A 55-year-old male presented with a rapidly growing, painful palpable mass in the left groin region involving the femoral nerve and blood vessels. Magnetic resonance imaging performed 18 days before surgery revealed a 10.5 x 7.6 x 11.0 cm large intramuscular tumour. No metastases were detected on CT scans of the chest, abdomen and pelvic area performed 14 days before surgery. Microscopic evaluation of a biopsy revealed a high-grade malignant spindle cell sarcoma , NF1 (p.K354R), PTGS2 (intronic), LRP2 (p.Q4132E), KRAS (p.G12V), PRRC2C (p.R1257G) and GATA6 (p.A29A), as well as a frameshift deletion in PRG4 (p.R791fs)  and a custom in-solution capture panel, containing exons of 900 cancer-related genes, developed by the Norwegian Cancer Genomics Consortium  . The met, NF1 p.K54R, PTGSGATA6 and PRG4, with the lowest allele frequencies in the primary tumour, were not detected in the plasma samples. The mean sequencing depth of the six detected mutations in all three plasma samples was 260x (11-474x), and the two undetected had a depth of 360x (199-433x). One new mutation in the splice site of RAD52, a C > T mutation with an allele frequency of 5.5%, was detected in the cfDNA collected before surgery. This region was sequenced at high coverage, but the mutation was not observed in the primary tumour nor in the plasma samples collected at later time points ) in all plasma samples  in allThe level of total cfDNA was monitored during disease progression. High quantity of cfDNA was detected one day before surgery (110 ng/ml plasma), and a decrease was seen three days after surgery (76 ng/ml plasma). Six weeks after surgery, the quantity of cfDNA had increased to more than twice the initial level present before the surgery (316 ng/ml plasma) Fig. .COL2A1, NF1, PTGS2, LRP2, KRAS and PRRC2C. The ctDNA level in plasma collected one day before the surgery (Plasma1) was high, and comparable to the level in primary tumour. Three days after surgery, the ctDNA level had dropped, but was still detectable in plasma (Plasma2). In the sample collected six weeks after surgery (Plasma3), there was again an increase in ctDNA level similar to the levels before surgery  and NF1 (p.K354R) were predicted by dbNSFP [TP53 and activation of KRAS induced quick formation of spindle-cell sarcoma in soft tissues in double transgenic mice [TP53 found in the primary tumour strengthens the histology observed in the primary tumour. The patient in our study had an unusually aggressive spindle-cell sarcoma, supporting KRAS not only as biomarker, but as a driving gene of the disease progression. NF1, a tumour suppressor that functions as a negative regulator of the Ras pathway, is among the most frequently mutated genes in several subtypes of sarcomas. Germline and somatic loss of NF1 in neurofibromatosis patients cause malignant peripheral nerve sheath tumours [NF1 mutations, including deletions, have been reported in a wide variety of paediatric and adult soft-tissue sarcomas with complex karyotypes [KRAS or NF1 are available, our study shows that repeated sampling using liquid biopsies opens new possibilities to identify and monitor biomarkers that can be used in targeted therapies.In this study, we prospectively collected primary tumour and normal sample material at surgery and several plasma samples during the disease course of a high-grade soft tissue sarcoma patient. Targeted resequencing of the primary tumour and the normal sample identified eight somatic mutations of which six were also present in the plasma samples. Among the mutations, y dbNSFP  to have nic mice . The hom tumours  and GIST tumours . In addiryotypes , 25. AltGATA6 and the frameshift deletion in PRG4 could not be detected in the plasma samples. Although these regions had a high coverage, these mutations had the lowest allele frequency in the primary tumour and this may thus be a sensitivity issue. However, it is also possible that the cells containing these mutations did not release DNA into circulation. This shows that the ctDNA gives a good representation of the genomic profile of the tumour, but also emphasize the need to use several mutations when monitoring disease development. A mutation in RAD52, a gene involved in DNA recombination, was detected in the plasma collected before surgery, but was not observed in the primary tumour nor in the plasma sample collected after surgery or at recurrence. One explanation for this may be tumour heterogeneity where the cells containing this mutation were not present in the part of the primary tumour that was sequenced and was not retained during disease progression. Discrepancy of mutation pattern between DNA from primary tumours and plasma have also previously been reported [The synonymous mutation in reported , 27, shoThe allele frequencies of the six mutated genes in the cfDNA represent the ctDNA level during disease progression. Three days after surgery, ctDNA was still detectable in the liquid biospy. cfDNA has a rapid clearance, with reported half-life from 15 min  to 13 h The cfDNA can originate from both normal and tumour cells. Based on the high mutated allele frequencies determined in plasma, the initial level of cfDNA is dominated by DNA from the tumour. Most of the cfDNA present three days after surgery is believed to originate from tissue injury and inflammation of normal cells as a consequence of the extensive surgery, which would explain the apparently higher normal contribution to the cfDNA at this time point. After six weeks, there was a large increase in cfDNA accompanied with an increase of the mutated allele frequencies. Thus, the quantities of cfDNA present in the plasma reflected the clinical status of the patient due to the fact that most of the cfDNA released during disease progression was tumour derived.This study is the first report of using targeted resequencing of cfDNA from serial plasma samples to monitor disease progression in a soft tissue sarcoma patient. The findings show that the level of tumour-specific mutations in liquid biopsies is correlated to disease course in sarcomas, including clinical manifestation of metastatic disease. The longitudinally collected ctDNA allow for near real-time monitoring of the tumour genome during disease progression, and the ctDNA gives a good representation of the genomic profile of the tumour supporting the use of ctDNA from plasma as a liquid biopsy.


Metrics derived from Twitter and other social media—often referred to as altmetrics—are increasingly used to estimate the broader social impacts of scholarship. Such efforts, however, may produce highly misleading results, as the entities that participate in conversations about science on these platforms are largely unknown. For instance, if altmetric activities are generated mainly by scientists, does it really capture broader social impacts of science? Here we present a systematic approach to identifying and analyzing scientists on Twitter. Our method can identify scientists across many disciplines, without relying on external bibliographic data, and be easily adapted to identify other stakeholder groups in science. We investigate the demographics, sharing behaviors, and interconnectivity of the identified scientists. We find that Twitter has been employed by scholars across the disciplinary spectrum, with an over-representation of social and computer and information scientists; under-representation of mathematical, physical, and life scientists; and a better representation of women compared to scholarly publishing. Analysis of the sharing of URLs reveals a distinct imprint of scholarly sites, yet only a small fraction of shared URLs are science-related. We find an assortative mixing with respect to disciplines in the networks between scientists, suggesting the maintenance of disciplinary walls in social media. Our work contributes to the literature both methodologically and conceptually—we provide new methods for disambiguating and identifying particular actors on social media and describing the behaviors of scientists, thus providing foundational information for the construction and use of indicators on the basis of social media metrics. Twitter and other social media have become important communication channels for the general public. It is thus not surprising that various stakeholder groups in science also participate on these platforms. Scientists, for instance, use Twitter for generating research ideas and disseminating and discussing scientific results –3. Many Quantitative investigations of scholarly activities on social media—often called altmetrics—can now be done at scale, given the availability of APIs on several platforms, most notably Twitter . Much ofA crucial step towards empirical validation of the broader impact claim of altmetrics is to identify scientists on Twitter, because altmetric activities are often assumed to be generated by “the public” rather than scientists, although it is not necessarily the case. To verify this, we need to be able to identify scientists and non-scientists. Although there have been some attempts, they suffer from a narrow disciplinary focus –10 and/oHere we present the first large-scale and systematic study of scientists across many disciplines on Twitter. As our method does not rely on external bibliographic databases and is capable of identifying any user types that are captured in Twitter list, it can be adapted to identify other types of stakeholders, occupations, and entities. Our study serves as a basic building block to study scholarly communication on Twitter and the broader impact of altmetrics.product- vs. producer-centric perspectives. The former examines the sharing of scholarly papers in social media and its impact, the latter focuses on who generates the attention.We classify current literature into two main categories, namely Product-centric perspective. Priem and Costello formally defined Twitter citations as “direct or indirect links from a tweet to a peer-reviewed scholarly article online” and distinguished between first- and second-order citations based on whether there is an intermediate web page mentioning the article [ article . The acc article .r = 0.003) [Many studies argued that only a small portion of research papers are mentioned on Twitter , 14–19. = 0.003) ; howeverProducer-centric perspective. Survey-based studies examined how scholars present themselves on social media [Nature in 2014 revealed that more than 80% were aware of Twitter, yet only 13% were regular users [al media –30. A laar users .A handful of studies analyzed how Twitter is used by scientists. Priem and Costello examined 28 scholars to study how and why they share scholarly papers on Twitter . An analNote that these studies first selected scientists outside of Twitter and then manually searched their Twitter profiles. Two limitations thus exist for these studies. First, the sample size is small due to the nature of manual searching , 12, 31.http://www.bls.gov/soc/) released by the Bureau of Labor Statistics, United States Department of Labor. We use SOC because not only it is a practical and authoritative guidance for the definition of scientists but also many official statistics  are released according to this classification system. SOC is a hierarchical system that classifies workers into 23 major occupational groups, among which we are interested in two, namely (1) Computer and Mathematical Occupations (code 15-0000) and (2) Life, Physical, and Social Science Occupations (code 19-0000). Other groups, such as Management Occupations (code 11-0000) and Community and Social Service Occupations (code 21-0000), are not related to science occupations. From the two groups, we compile 28 scientist occupations  system , for each user, to get all the lists containing this user, and then infer whether this user is a scientist by analyzing the names and descriptions of these lists. However, this method is highly infeasible, because (1) most users are not scientists, (2) the distribution of listed counts is right-skewed: Lady Gaga, for example, is listed more than 237K times , and (3) Twitter API has rate limits. We instead employ a previously introduced list-based snowball sampling method [In principle, we could use Twitter’s g method  that stag method   and put those who have not been visited into the queue. The two steps are repeated until the queue is empty, which completes the sampling process. Note that to remove many organizations and anonymous users as well as to speed up the sampling, we only consider users whose names contain spaces. We acknowledge that this may drop many users with non-English names or the ones who do not disclose their names in a standard way. Also note that this procedure is inherently blind towards those scientists who are not listed.We use the snowball sampling (breadth-first search) on Twitter lists. We first identify seed users  and put From the sampling procedure, we get 110, 708 users appearing in 4, 920 lists whose names contain scientist titles. To increase the precision of our method, the final dataset contains those users whose profile descriptions also contain scientist titles. A total number of 45, 867 users are found.For each of the 45, 867 identified scientists, we obtain their followers, followings, and up to 3, 200 most recent statuses  using Twitter APIs. In total, we get 88, 412, 467 following pairs and 64, 449, 234 statuses. With this dataset, we ask the following questions:What are the demographics of identified scientists on Twitter, in terms of discipline and gender?What are the URLs scientists post in their tweets?How do scientists follow/retweet/mention each other on Twitter and who are the most “influential” scientists in these interactions?These questions are necessary for the validation and appropriate utilization of altmetrics for research evaluation.We investigate the demographics of identified scientists in terms of discipline and gender.In contrast to previous analyses that either focused on a single discipline –10 and/oTo identify the discipline of each scientist, we leverage the compiled list of scientist titles. They are searched in profile descriptions and in assigned list names. Whereas profiles provide us information about how scientists perceive themselves, list names tell us how they are perceived by others. When searching, we begin with longer names and then move on to shorter ones. For instance, “I am an evolutionary biologist” will be matched with “evolutionary biologist” not with “biologist.” When multiple matches are found, each of them will be counted once. From profile descriptions, we obtain a total of 25, 798 (56.2%) users whose profile descriptions contain at least one scientist title, suggesting that a majority of “perceived” scientists identify themselves as scientists. When extracting titles from list names, there are 24, 635 (53.1%) users who are included in at least one list whose name contain scientist titles. Based on the titles extracted from profiles and list names, we now assign each user a final title or titles. We give more weight to titles from profiles by using profile information first when they are available. If this fails, we choose the title that appears the most times in the lists. With this procedure, we assign disciplines to 30, 793 (67.1%) users. http://www.bls.gov/oes/current/oes_nat.htm), which lists the size of workforce for each occupation. We aggregate the number of scientists onto the OES minor level , and We investigate whether some disciplines are over- or under-represented in social media by comparing the results in http://www.census.gov/topics/population/genealogy/data/1990_census/1990_census_namefiles.html), resulting in 11, 910 females and 18, 882 males. For the remaining unknown users, we detect their gender by using a facial feature detection service provided by Face++ (http://www.faceplusplus.com/detection_detect/). The input of this service is the URL of the image, which we use the profile image URL provided by Twitter, and one of its returned values is the gender associated with a confidence value. We only keep the gender results with confidence greater than 90. Combining the two methods, we are able to identify the gender for 71.9%  of the sample. Of those identified, 38.6% were female and 61.4% were male, or the female to male ratio is 0.629.To identify gender, we first remove two common prefixes (“Dr.” and “Prof.”) and then search the first names in the 1990 US census database of frequently occurring first names , leading to the female-male ratio 21%/24% = 0.875 (the ratio for Internet users is 0.99.). Regarding scientific authorships, the ratio ranges from 0.179 (Iran) to 0.754 (Poland), and is 0.428 for US [We compare the female-male ratio of the sampled scientists on Twitter to the ones derived from two other samples, namely general Internet users and offline scientific authorships. A recent report from the Pew Research Center shows that 21% and 24% of female and male Internet users use Twitter , and Springer (link.springer.com) appear in the top. Journals like Science, PNAS, and PLoS ONE also attract much attention on Twitter.We study tweet contents posted by scientists. We specifically focus on URLs to understand sharing of scientific articles on Twitter. To do so, we extract URLs from tweets and retweets, ignoring replies. We only consider those generated from the retweet button as retweets and extract URLs from their original tweets. Noting that many top domains are shortened URLs , we expand them and extract domain names. http://blogs.lse.ac.uk) is popular among political scientists, economists, and sociologists.To understand disciplinary differences of the posted URLs, s of (re)tweets that contains URLs referring to scientific websites to the total number of (re)tweets that contains URLs. s by disciplines. Clearly, the fractions are small across all disciplines, while biological scientists—biologists, neuroscientists, and ecologists—post more tweets referring to scientific domains. For other types of scientists, the fraction is smaller than 0.2 for nearly all of them. This suggests that for most scientists on Twitter, sharing links to scientific domains is a minor activity.To understand to what extent scientists share scientific URLs, we calculate for each user the fraction a to b means that a follows b. In the retweet network, a directed link pointing from a to b is weighted, with the weight representing the number of times that a has retweeted b’s tweets. In the mention network, a link is also directed and weighted, and the weight indicates the number of times that a has mentioned b in a’s tweets. We investigate how scientists connect with each other, by examining the follower, retweet, and mention networks between them. In the follower network, a directed and unweighted link from user d← or in-strength s←, PageRank PR, and k-core number k in the three networks. We observe that there are some overlaps between d← (s←) and PR across the three networks and that top scientists in terms of k-core are different from those in terms of the other two measures. Regarding individual users, Neil deGrasse Tyson (@neiltyson), an astrophysicist, is ranked the first under degree and PageRank for all the three networks.Given the three networks, we investigate the most influential—operationalized by network centralities—scientists on Twitter. k-core number is less heterogeneous than the other two centralities across the three networks, and the distributions of PageRank are similar for the three networks. The heterogeneity in centrality distributions raises the question of how attention is distributed among disciplines. We thus calculate, for each centrality in each network, the sum of centrality values of users in each OES minor group  divided by the total values of the centrality. Going beyond top nodes, we show in Assortativity quantifies the tendency that nodes with similar attributes are connected . We obseOur work presents an improvement over earlier methods of identifying scientists on Twitter by selecting a wider array of disciplines and extending the sampling method beyond the paper-centric approach. Our method may serve as a useful step towards more extensive and sophisticated analyses of scientists on Twitter—it cannot be assumed that the population of scientists on Twitter is similar in composition and behavior to the population of scientists represented in traditional bibliometric databases. Therefore, sampling should be independent of these external data and metrics. Furthermore, in seeding with terms from the Standard Occupational Classification provided by the Bureau of Labor Statistics, we are able to classify both scholarly and practitioner scientific groups, thus widening the conceptualization of scientists on Twitter.The triangulation of list- and bio-based classifications of scholars allows us to integrate two perspectives on identity: how scientists self-identified and how they were identified by the community. Our approach favors precision over recall; that is, we feel confident that those identified were scientists, but there is a much larger population of scientists who were not identified in this way.Our disciplinary analyses suggest that Twitter is employed by scholars across the disciplinary spectrum—historians were widely represented, as were physicists, political scientists, computer scientists, biologists, economists, and sociologists. Practitioners were also highly represented—psychologists and nutritionists were in the top five in terms of disciplines with the highest number of identified members. However, a large percentage was also explicitly academic scholars: self-identified students and faculty members comprised 21.9% of the total population . Our anaOf those whose gender could be identified, 38.6% were female and 61.4% were male. This represents a more equal representation of women than seen in other statistics on the scientific workforce, such as number of publications , suggestThe Guardian, New York Times, and the BBC. However, scientists also have a distinct imprint of scholarly sites, such as generalists publications  and reinforce the academic oligarchy of journal publishers [As might be expected, scientists tweet in much the same way as the general population: Instagram, Facebook, YouTube are among the most tweeted domains, along with general news sites such as blishers . The popblishers .We operationalized centralities in three ways: by followers, retweets, and mentions. Social and life scientists dominate these networks and mathematicians and computer scientists are relatively isolated. However, once these centralities are normalized by the size of the group, social scientists actually underperform, given their size. This is imperative information for the construction of indicators on the basis of these metrics. Just as it is standard bibliometric practice to normalize by field, so too should altmetric practices integrate normalization, given the uneven distribution of disciplines represented on these platforms.Analysis of assortativity suggests that disciplinary communities prevail in the unfiltered realm of social media—scholars from the same disciplines tended to follow each other. This could suggest a negative result in terms of broader impact of social media metrics—if disciplinary walls are maintained in this space, it may not provide the unfettered access to scholarship that was promised. Furthermore, networks of communities reveal some isolation: e.g., although they represent a large proportion of the total users identified, historians are largely isolated in the Twitter network.Our work has the following limitations. First, the reliance of Twitter lists leads to our method inherently blind towards those scientists who are not listed. Furthermore, the use of lists may skew towards the elite and high profile science communicators . Second, in the sampling process, the exclusion of users whose names are without spaces biases the sample towards English-speaking users and causes many scientists not discovered. Third, the existence of private lists prohibits us to get the members there and affects further discovery of new users. Fourth, how list members were curated is largely unknown, and this might be done automatically and thus decrease the precision of identified scientists. Fifth, in the post-processing, the filtering of users whose profile descriptions do not contain scientist titles biases the sample towards self-disclosed scientists.In this work, we have developed a systematic method to discovering scientists who are recognized as scientists by other Twitter users through Twitter list and self-identify as scientists through their profile. We have studied the demographics of identified scientists in terms of discipline and gender, finding over-representation of social scientists, under-representation of mathematical and physical scientists, and a better representation of women compared to the statistics from scholarly publishing. We have analyzed the sharing behaviors of scientists, reporting that only a small portion of shared URLs are science-related. Finally, we find an assortative mixing with respect to disciplines in the follower, retweet, and mention networks between scientists.Future work is needed to examine the use of machine learning methods  by leverS1 Text(PDF)Click here for additional data file.S1 Fig(PDF)Click here for additional data file.S1 Table(PDF)Click here for additional data file.S2 Table(PDF)Click here for additional data file.S3 Table(PDF)Click here for additional data file.S4 Table(PDF)Click here for additional data file.S5 Table(PDF)Click here for additional data file.S1 Data(TXT)Click here for additional data file.


Identifying appropriate preclinical cancer models remains a major challenge in increasing the efficiency of drug development. A potential strategy to improve patient outcomes could be selecting the ‘right’ treatment in preclinical studies performed in patient-derived xenografts (PDXs) obtained by direct implants of surgically resected tumours in mice. These models maintain morphological similarities and recapitulate molecular profiling of the original tumours, thus representing a useful tool in evaluating anticancer drug response. In this review, we will present the state-of-art use of PDXs as a reliable strategy to predict clinical findings. The main advantages and limitations will also be discussed. PDXs maintain the cellular and histological structure of the original tumour and include critical stromal elements, which provide sustenance under periods of extensive growth [In recent years, patient-derived xenografts (PDXs), where tumour fragments from patients are directly implanted in immunodeficient mice and then passed e growth . Moreovee growth , 5. Intee growth , 7. All PDXs are developed by implanting fresh human tumour fragments in immunosuppressed mice. Usually, the time required for the tumour to take is between 2–4 months, although failure of engraftment should not be ascertained until at least 6 months and beyond .F1), tumours initially appeared but a subsequent regression was observed in 3 out 5 mice  nude mice, which lack a thymus and are unable to produce T cells; ii) NOD-SCID and SCID-beige mice, which lack functional T, B and NK cells; iii) NOD-SCID IL2RGamma null , in which the NK cell activity is completely absent. Due to different immunological impairments, it is assumed that the more permissive mouse strains such as NOD-SCID, SCID or NSG, can strongly increase the efficiency of xenotransplantation, as compared to nude mice. Indeed, a very low tumour rate take 10–25%) was reported after implanting tumour fragments of different histotypes in nude mice –10. The –25% was ice Fig. . On the Concerning the tumour engraftment sites, the most common site is the subcutaneous (s.c.) injection of the tumour administered through a small incision made on the dorsal region of the mice. A modification of this classical s.c. procedure has recently been proposed, consisting in the positioning of specimens in a dorsal intramuscular pocket of the mice. The authors reported that in esophageal PDX models this technique produced an improved tumour take-rate (72%) compared to the 17% observed with the standard subcutaneous method , attribuEven though many new antineoplastic compounds have shown favorable tumour responses in preclinical studies, more than 95% of novel therapeutics have failed to confirm efficacy in clinical trials. Many factors are responsible for this high failure rate, including the lack of predictive preclinical cancer models . Thus, gThe study by Bertotti et al.  performeThe need for better, more clinically predictive models of epithelial ovarian cancer which account for 90% of ovarian cancer, led Giavazzi’s group  confirmsIn the search for effective therapies for unresectable gastric cancer, experiments performed on PDXs deriving from 8 patients demonstrated that Regorafenib, a multikinase inhibitor with activity against a range of protein kinases involved in oncogenesis , angiogenesis (VEGFR1–3 and TIE2), and maintenance of the tumour microenvironment (PDGFR and FGFR), was very active in reducing the growth of tumours in mice. Looking at the mechanisms involved in the antitumoral activity of these compounds, the authors reported a reduction in angiogenesis and proliferation associated with apoptosis induction . InteresKRAS genotype for the clinical efficacy of anti-EGFR therapy. In fact, while WT KRAS PDXs were sensitive to Cetuximab treatment [KRAS mutations were unresponsive to the treatment [Notably, PDXs could also be useful models for identifying predictive biomarkers of response to targeted therapies. For example, recently published studies on colon cancer PDXs confirm clinical data regarding the key role of WT reatment , PDXs bereatment  and thesEGFR Exon19 Del. activating mutation responded completely to Gefitinib, while PDXs with KRAS mutations or EGFR wild-types were insensitive to Gefitinib treatment. Even though the authors were not able to report response to Gefitinib in matched patients, these results are consistent with that reported in clinical trials [The utility of PDXs in supporting a precise selection of patients for EGFR-targeted therapies such as Gefitinib has also been demonstrated . These al trials , thus vain vivo preclinical studies and clinical trials could be performed in parallel, with the aim to specifically target the unique cancer of a patient or subgroup of patients. In particular, the concept of co-clinical trials refers to studies capable of defining a patient selection strategy based on molecular abnormalities or identifying mechanisms of resistance to antitumoral therapies, for the development of precision medicine aimed at personalizing anticancer treatment. In this context, PDXs could be also used as an ‘avatar’ model, in which PDXs obtained from a patient enrolled in a clinical trial could be treated with the same therapy administered to the patient, thus permitting to identify biomarkers of sensitivity or resistance to treatments.Evidence showing that PDXs have a high predictive power for the efficacy of standard and novel anticancer therapeutics has encouraged the idea to employ this platform in the so-called co-clinical trials, where in vitro genetic screen and functional studies on CRC showed that dual blockade of EGFR and MEK prevents acquired resistance and as a result performed experiments in vivo on PDXs derived from a CRC patient carrying a quadruple wild-type gene profile  which recapitulate the molecular profile of patients sensitive to anti-EGFR antibodies. Treatment of PDXs with the anti MEK Pimasertib alone only slightly reduced tumour growth, while Cetuximab treatment was very effective in reducing tumours to more than 70%. The subsequent regrowth of these tumours, showed resistance to drug re-challenge thus resembling the clinical findings. In contrast, the Cetuximab/Pimasertib combination elicited a complete response as tumours remained undetectable for more than 6 months. These results led authors to suggest that the use of ‘ab initio’ combination treatment could inhibit the development of resistant tumours showing molecular heterogeneity as well as highlight the usefulness of PDXs in establishing a very effective antitumoral strategy.Most intriguingly, since a major cause of failure of treatments is the acquired resistance of tumours , the useTo search for a second-line personalized treatment in melanoma patients acquiring resistance to BRAF inhibitors, Krepler et al.  establisA paradigmatic example of the use of PDX as an “avatar” for personalized cancer treatment is reported by Bousquet et al. . In partThese examples demonstrate that PDX models integrated with targeted sequencing and phosphoproteomic platforms, provide the preclinical basis for identifying more effective therapies both in the first and second-line targeted inhibitor strategies, also for the repositioning and/or repurposing of previously approved drugs.Although PDXs possess notable advantages compared to classical xenografts as described above, they do have some limitations that cannot be omitted. Importantly, overcoming these issues could increase this model’s potential for improving therapeutic application of antineoplastic compounds.One of the major limitations of PDXs is that tumours fail to progress or to metastasize and therefore do not retain all patterns of the disease course observed in patients. One strategy to overcome this disadvantage is represented by the engraftment of tumour specimens in the orthotopic sites of origin. To this purpose, several reports have shown that patient-derived orthotopic xenografts (PDOXs) could represent a powerful tool for addressing this key point in the science of preclinical modelling. Particularly, DeRose et al.  reportedAt the same time the s.c. implantation does not represent the site of origin, thus limiting studies on evaluating the role of the tumour microenvironment as it is well known that the cells of the tumour vasculature, fibroblasts and inflammatory cells, interacting with tumour cells, are important in tumour biology and that the microenvironment regulates cancer-drug sensitivity . Thus, tA further limitation of the model is that mice used for engraftment have a severely compromised immune system which poses a disadvantage for the full exploitation of PDX technology, since the contribution of immune-cell function hinders the proper evaluation of tumour growth and patient response in these models. This is particularly true in certain tumours such as melanoma in which progresses in treating this neoplasia have been made with targeted immunotherapy , 39. The3) grown in one mouse and implanting small pieces of the mass (15–20 mm3) in several mice for propagation. Our observations seem to confirm this hypothesis as demonstrated in PDXs originating from one colorectal cancer patient and treated with a G-quadruplex (G4) ligand, one mouse showed complete response, two mice partial response followed by a rapid disease progression and no-response was elicited in one mouse (Fig. The intratumour heterogeneity could have an impact on the interpretation of data stemming from PDXs as they are usually developed from small fragments obtained by larger biopsies. At the same time, the passages in mice could increase this spatial intratumoral heterogeneity since propagation is obtained by cutting the tumour mass (300–500 mm mass 15–0 mm3 in One critical aspect concerns the maintenance of PDXs in the genetic integrity of parental tumours and the degree of alterations occurring across the passages into new mice. To this purpose there are many examples throughout literature reporting that in the initial passages, PDXs retain the histological, immunohistochemistry, gene expression, copy numbers and chromosomal stability profile of the original patient tumour , 4. ModiIn contrast, genetic changes that occurred via each passage to a new mouse host seem to represent genomic rearrangements intrinsic to tumour progression. In particular, in breast cancer PDXs it was observed that tumours in mice showed a pronounced mutational status or aggressiveness of tumour characteristics, sometimes comparable to patient metastases compared to primary tumours . These oPerhaps one major obstacle in PDX modelling for co-clinical trials and personalized medicine is the long timeframe required for engraftment. In fact, the tumour latency calculated as the time between implantation and the development of a progressively growing xenograft tumour can range from 2 to 12 months. Considering that tumours have to be passaged several times in mice to generate a sufficient number of “avatars”, this means that individual patients with a rapidly progressing disease could not benefit from PDX studies. To this purpose, performing drug testing in PDXs during the period of standard therapy could be a useful strategy in view of the second-line treatment based on PDXs results.PDX models are a relevant preclinical platform and represent a significant challenge for oncology research as they, more accurately, reflect human tumour biology than any other existing models. If PDXs are viewed as complementary to other experimental models, the use of PDXs should lead to a higher rate of success in identifying new and more effective therapeutic strategies and in transitioning into individualized therapy. The aforementioned limitations of this model, the high costs associated with maintaining mouse colonies and regulatory issues have hindered the full exploitation and widespread utilization of this methodology, therefore vast efforts are needed to refine the model and overcome these challenges. The collaboration between private and public institutes devoted in the fight against cancer, in developing and characterizing large collections of PDX models from different cancer types, will accelerate progress in the area of drug development. In conclusion, the long-term benefits of using more relevant preclinical models of human tumour biology merit these efforts and expenses.


Our findings bear important consequences on sweep efficiency and fluid mixing and reactions, which are key in applications such as microfluidics to carbon geosequestration, energy recovery, and soil aeration and remediation.We present a systematic, quantitative assessment of the impact of pore size disorder and its interplay with flow rates and wettability on immiscible displacement of a viscous fluid. Pore-scale simulations and micromodel experiments show that reducing disorder increases the displacement efficiency and compactness, minimizing the fluid-fluid interfacial area, through (i) trapping at low rates and (ii) viscous fingering at high rates. Increasing the wetting angle suppresses both trapping and fingering, hence reducing the sensitivity of the displacement to the underlying disorder. A modified capillary number Ca In many of the challenges we face today as geoscientists, in particular in the context of water and energy resources, fluid invasion into a porous soil or sediment is a key process. Examples include hydrocarbon migration and recovery, methane venting from hydrate-bearing sediments, drying and wetting of soils, and carbon geosequestrationheterogenous pore geometry, leads to ramified, preferential flow paths or “fingering”. Predicting the emergent patterns is challenging, because of the sensitivity to pore-scale details and the large number of coupled mechanisms and governing parameters which vary over a wide range of values and scales32 sequestrationThe complex interplay between capillary, viscous, and gravitational forces, wettability effects, and the underlying μdv/γ) modifies the pattern depending on the fluids viscosity ratio, M = μd/μi, towards (i) viscous fingering (VF) for an unfavorable ratio, M > 1, or (ii) compact (CO) for a favorable ratio (M < 1)8μ is the viscosity, v is the characteristic fluid velocity, and γ is the interfacial tension, where subscripts d and i denote defending and invading, respectively.The practical importance of fluid displacement motivated intensive research, that identified several important mechanisms governing the displacement efficiency. In disordered media, slow displacement of a wetting fluid  leads to a patchy pattern with multiple islands of defending fluid, called capillary fingering (CF). The process of forming these islands is called trapping, as lack of fluid continuity between them inhibits their mobilization. Increasing the flow rate  and underlying mechanisms (e.g. hydrodynamic instabilities), we use “compact”, “efficient” or “stable pattern”.Another important property is wettability, namely the relative affinity of the fluids to the solid. Increasing affinity of the invading fluid  smoothes the invasion front, even at high, unfavorable size disorder alone, excluding other types of heterogeneity including in wetting propertiescorrelations such as layers or dual porosity media14Experimental and computational capabilities limit the number of mechanisms that can be modeled. Here, we focus on the following subset: capillarity, viscosity, wettability, and their coupling with random disorder in pore and/or particle sizes. We exclude here gravity and buoyancy effects. We also focus on Disorder in pore sizes is inherent in natural media such as soils and rocks6either capillary or viscous forces are dominant seems to be univocally accepted. For slow drainage, high disorder was shown to promote trapping, leading to a transition from CO to CF18192021222320M22packing disorder.The effect of disorder on the invasion morphology when both viscosity and capillarity are important, the qualitative paradigm  produces a more CF-like pattern, increasing the transitional Ca between CF to VF, CaCF/VF18212223CF/VF, promoting a more CF-like pattern, sweep efficiency should increase  at a fixed rate Q in samples of different disorder in particle sizes. Details of the simulations and experiments are provided in Methods and d drawn from a uniform distribution of width λ, r, with a triangular distribution), see We consider radial displacement of a viscous fluid by an inviscid fluid , we reproduce the transition from CF to VF as the rate increases in drainageθ < 90°, θ measured through the defending fluid, see θ towards imbibition (θ > 90°), reducing trapping11λ enhances the displacement efficiency, by inhibiting trapping and formation of thin, tortuous fingers at low and high rates, respectively. While in highly-disordered systems the pattern is random (showing no dependence on the underlying structured lattice), reducing λ amplifies the impact of the underlying lattice, suppressing both trapping and fingering, eventually resulting in the following transitions: (i) from CF to CO in slow drainage22M = μd/μi ≈ 55. Reducing λ also suppresses the impact of wettability; that is, the competing effects of reducing λ and increasing θ offset each other  of geometry identical to the simulations, displacing glycerol by air . The experimental patterns support our findings that reducing λ enhances the displacement efficiency by (i) suppressing trapping at low Ca, leading to a transition from CF to CO; and (ii) reducing the number of tortuous fingers, increasing their width (from VF to OD) at high Ca (λ on the invasion dynamics: (i) the transition in the mode of front propagation from radially-symmetric and continuous (CO) to intermittent and asymmetrical (CF) as λ is increased at low rates  at high rates.To validate our numerical findings, we conducted micromodel experiments with two cells of different disorder , they are not identical. Potential causes for this mismatch include (1) manufacturing defects in pillar placement and shape , insets 9w, interfacial areas Ainter and Afront, and breakthrough saturation S. The interfacial areas (lengths in 2-D) are computed from the ratio of interfacial and invaded pores, including trapped regions (Ainter) or excluding them (Afront). The areas are normalized by the invaded volume Vinv (area in 2-D), and multiplied by the lattice spacing a to make them dimensionless. The finger width w is evaluated by skeletonizing the pattern with a Voronoi algorithm, and measuring the distance (in lattice units a) of the medial line from the interface. In evaluating w we include small clusters trapped within fingers, unlike some previous studies where these were ignoredw).We characterize the patterns through their finger width θ) of increasing disorder λ, manifested as an increase in Ainter and Afront , and a decrease in w , see λ in imbibition (high θ): (i) reducing the variation in capillary thresholds, increasing compactness; and (ii) inhibiting cooperative events which smooth the interface, hence decreasing compactness.Our simulations point to the persistent effect , where the radially-symmetric invasion (Video 1 in a). In contrast, high disorder provides constrictions with high entry pressures that remain non-invaded . Overlaps, which increase in occurrence with θ (and do not appear below ~60°), stabilize imbibition patterns by suppressing fingering and trappingλ = 0.82 and 0.22, demonstrate that pore-size homogeneity hinders overlaps. Since disorder also promotes trapping, the two effects counteract, leading to the small sensitivity to λ in slow imbibition; this is particularly noticeable for Afront, which is more affected by trapping than Ainter or w  and high λ, the patchy CF-like pattern traps a significant portion of the defending fluid (θ), lowering disorder inhibits both cooperative pore filling (λ (cf. within thick fingers (CF) at low Ca (between thin fingers (VF) at high Ca  capillary forces δpcap through the entry threshold distribution which controls the invasion order along the interface , as well as (ii) viscous forces through the permeability k, a nonlocal effect, not accounted for in previous works18212223k as an effective permeability: considering finger growth in the radial direction, we use the weighted harmonic mean of the local (interpore) permeabilities Here, we point to an inherent shortcoming in the above definition when disorder is introduced: the assumption r distribution) decreases the size of the smallest throats (“bottlenecks”) and thus the permeability k , it increases δpvis. If the accompanying increase in δpcap is smaller, this would amount to increasing Ca*.The main outcome of rc and rc arises from the characteristic threshold, δpcap ~ γ/rc, whereas rc in r, the distribution is dominant; thus, we evaluate rc using the standard deviation, rc = σ(r). In imbibition, the increasing occurrence of overlaps with λ . This indicates a direct relationship between Ca* and λ  in the literature18212223λ as the wetting angle θ increases (highlighted in λ = 0.82 than for λ = 0.22 for drainage (θ = 5°), vs. only ~2.5 for imbibition (θ = 120°), see inset in As samples with higher We study the impact of random pore size disorder on the fluid-fluid displacement in porous media. We use a novel pore-scale model which provides a mechanistic description of both drainage and imbibition. Our numerical results are validated against micromodel experiments, and explained theoretically by scaling analysis. To the best of our knowledge this is the first systematic, quantitative study of the impact of disorder and its interplay with flow rates and wettability.λ increases the pattern compactness, with a smoother fluid-fluid interface. We demonstrate that the effect of disorder depends on its coupling with flow rate and wettability: (i) at low rates, a more pronounced impact of λ on capillary thresholds and hence on the order of invasion and trapping; (ii) at high rates, increasing λ strongly increases the viscous pressure drop by decreasing pore connectivity, promoting pressure screening and viscous instabilities, increasing the number of thin, tortuous fingers; and (iii) increasing the wetting angle θ stabilizes the invasion pattern by reducing trapping and smoothing the interface, thus minimizing the impact of disorder. At low λ, the underlying pore geometry (lattice structure) becomes dominant, in particular in imbibition, leading to symmetrical growth of faceted, compact pattern at low Ca and dendritic fingers at high Ca.We show that lowering disorder * providing a direct relationship between Ca* and λ, that is a lower transitional CaCF/VF value at higher λ, in par with previous works18212223While our observation that decreasing disorder increases the sweep efficiency agrees with previous studies182021222324252 geosequestration by carbonate mineralizationIn summary, our work offers a fresh perspective into a long-standing paradigm of significance in processes where efficiency of fluid extraction/injection and mixing and reaction of the fluids are crucial. Increasing disorder promotes fingering, which limits the recovery of subsurface fluids such as hydrocarbons16fundamental understanding of the complex interactions among disorder, wettability and rates. Therefore, we choose the simplest representation (for both numerics and experiments) of a partially-wettable, disordered porous medium that retains the most crucial aspects of the behavior of such medium. We consider here the following model system: cylindrical solid pillars placed on a regular lattice , where a is the lattice spacing. Each particle triplet defines a pore with volume V connected to three neighboring pores by throats with aperture 0 < r ≲ a; to avoid closed throats due to particle overlap we enforce d ≪ h, such that the in-plane curvature is much larger than the out-of-plane curvature, Rin ≪ Rout. This allows us to approximate the meniscus as 2-D, with a radius of curvature We construct square-shaped samples of size Simulations are conducted with the model of Holtzman and Segre341924θ, and has a radius of curvature R = γ/Δp according to the Young-Laplace law. Here Δp is the pressure jump across the meniscus. The angle θ is measured through the defending fluid (i.e. θ < 90° for drainage), and represents an effective advancing angle, which includes dynamic effectsR and θ allows to resolve analytically the position and hence stability of each meniscus.We represent the fluid-fluid interface as a sequence of menisci, where each meniscus is a circular arcs which intersects a pair of particles at the prescribed contact angle θ. Overlap is a nonlocal mechanism as it is affected by menisci in multiple pores, acting to smooth the interface12burst, when the curvature exceeds a threshold set by the local geometry; (2) touch, when a meniscus intersects a third, downstream particle; and (3) overlap of adjacent menisci, destabilizing each other [33A crucial feature of our model is its account for cooperative pore-filling overlaps, which bch other . Once decle; and  overlap μm, respectivelyL = 100a) with λ = 0.22 and 0.52, however with lattice spacing a = 1 mm (vs. 0.5 mm in simulations). Pillar height of h = 3 mm was chosen to ensure sufficiently large aspect ratio h/r such that the meniscus can be approximated as 2-D, while small enough to minimize hydrostatic pressure and thus 3-D, out-of-plane effects inducing vertical flows. The lattice is embedded in a frame with a trench (of width 1 cm) around it to ensure evenly distributed withdrawal. The chip is sandwiched between two 1 cm-thick acrylic plates, with an outlet cross-sectional area Aout ≈ 5.5 · 10−4 m2.Micromodels allow visualization of the solids and fluids, making them a highly useful tool to study fluid displacement. Here, we use 3-D printing (“stereolithography”), an additive method fabricating free-form solids using a computer-aided design (CAD) file. A ProJet 3500 Multi Jet Printer (3D Systems Inc.) with “VisiJet M3 Crystal” plastic provided in-plane and out-of-plane resolution of 50 and 32 μd ≈ 1 Pa · s and γ ≈ 6.3 · 10−2 N/m at ~25 °C, Gadot Chemical Terminals LTD.). A high-viscosity fluid was selected to probe high Ca, where the CF–VF transition occurs. The contact angle  was measured to be 75° ± 5° using a sessile drop goniometer . Glycerol is withdrawn from ports at the cell corners by a syringe pump (Harvard Apparatus PHD ULTRA 70-3007) at a fixed rate Q, letting air (μi = 1.8 · 10−5 Pa · s) invade freely through a central inlet . We illuminate the cell from above with LEDs. To improve image contrast, the bottom acrylic plate was painted black, and the inner side of the top plate was sandpapered, causing dry areas to appear opaque.The cell is initially filled with glycerol .Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


In the article titled “Instructors' Perceptions of Mostly Seated Exercise Classes: Exploring the Concept of Chair Based Exercise” , there wThis work was supported by the Medical Research Council (MRC) Doctoral Training Grant (Grant no. MR/K500823/1) and the University of Manchester through the Faculty of Medical and Human Sciences. The authors would also like to thank Professor Dawn Skelton for her advice and Professor Chris Todd, Professor Skelton, and Dr. Maria Horne for their involvement in the original survey design.


Adrenal corticomedullary mixed tumours are very rare. Its mechanism is rarely reported. Here we report the first case of a corticomedullary mixed tumour resembling a “small adrenal gland” with distinct arrangement of the cortical and medullary layers. We further hypothesize regarding the tumorigenic mechanism of this tumour.A 58-year man had been diagnosed with diabetes and hypertension for 3 years. His 24-h urine vanillylmandelic acid (VMA) levels were slightly elevated. An abnormal circadian cortisol rhythm was noted, and his cortisol levels were not suppressed by dexamethasone. Abdominal computed tomography (CT) revealed a right adrenal gland lesion , while an enhanced CT showed enhancement and hypervascularization. The tumour was positive for adrenocorticotropic hormone, chromogranin A (CGA), and steroidogenic factor-1 (SF-1) on the tumour surface. Acetaldehyde dehydrogenase 1(ALDH1), CD44, CD133, Nestin, Nerve growth factor receptor (NGFR), and Sex determining region y-box 9(SOX9) staining were positive. Although administration of medications for diabetes and hypertension was stopped until surgery was performed, the blood sugar level and blood pressure were maintained after surgery.This is the first report about a possible mechanism by which cancer stem cells induce adrenal corticomedullary tumours. The adrenal gland contains a cortex and medulla, which originate from different germ layers. Thus, most primary neoplasms of the adrenal gland arise from either adrenal cortical cells or chromaffin cells of the adrenal medulla, and adrenal tumours generated by more than one cell type are rare. Even if two cell types coexist in the adrenal gland, most often, two separate tumours form. Adrenal cortex and medulla lesions coexisting in the same tumour to form adrenal corticomedullary mixed tumours are rarer. In the approximately 20 cases of adrenal corticomedullary mixed tumours reported to date –20, tumoA 58-year-old man with a history of type 2 diabetes and hypertension was admitted in June 2013 because of headache, loss of appetite, constipation, and wide fluctuations in both blood glucose levels (3.3–25.2 mmol/L) and blood pressure (147–180/70–120 mmHg) during the past three months, despite treatment with insulin, metformin, and amlodipine, furthermore, he had undergone subtotal gastrectomy for a stomach ulcer 28 years ago. The patient had no family history of diabetes, hypertension, malignancies, or other related diseases. Physical examination revealed a blood pressure of 119/83 mmHg with no physical signs of moon facies, buffalo hump, truncal obesity, or purple abdominal striae. The CT image revealed a circular, solid, soft tissue mass measuring 30 × 38 mm with a clear boundary in the right side of the adrenal gland. On contrast enhancement, the lesion appeared heterogeneous, with no calcification or necrosis. Enhancement and hypervascularization Fig.  also werA corticomedullary mixed tumour is defined as a single adrenal tumour mass containing an intimately admixed population of both adrenal cortical cells and pheochromocytes . CorticoCorticomedullary mixed tumours produce both cortisol and catecholamine, and therefore, signs and symptoms may arise from either tumour component. Hypersecretion of cortical and medullary lesions causes 40% of diabetes cases, 80% of hypertension cases, and 53.33% of Cushing’s syndrome cases . The typAs the adrenal cortex and medulla originate from different germinal layers , corticaConcurrent cortical and medullary tumours present as either adrenal collision tumours, in which cortical and medullary tumours develop independently but in close proximity without admixture at the interface , or cortIn summary, here we reported the first case of an adrenal corticomedullary mixed tumour with distinct layers of cortical and medullary cells resembling a “small adrenal gland”, which differed from previously reported corticomedullary mixed tumour types. We also hypothesize that tumour stem cells may contribute to the development of this tumour. Our findings provide a new insight into the tumorigenic mechanism of adrenal tumours, and may help future development in adrenal tumour interventions.