Strigolactones (SLs) constitute a group of plant hormones which are involved in multiple aspects of plant growth and development. Beside their role in shoot and root development and plant architecture in general, SLs are also involved in plant responses to nutrient deficiency by promoting interactions with symbiotic organisms and via promotion of root elongation. Recent observations on the cross talk between SLs and other hormones demonstrate that the inhibition of adventitious root formation by ethylene is independent of SLs. Additionally, it was shown that root exposure to SLs leads to the accumulation of secondary metabolites, such as flavonols or antioxidants. These data suggest pleiotropic effects of SLs, that influence root development. The discovery that the commonly used synthetic SL analogue racGR24 might also mimic the function of other plant growth regulators, such as karrikins, has led us to consider the previously published publications under the new aspects. This review summarizes present knowledge about the function of SLs in shaping root systems under optimal and nutrient deficiency conditions. Results which appear inconsistent with the various aspects of root development are singled out. Pisum sativum L. [Arabidopsis thaliana L. are more sensitive to drought stress in comparison to the wild-type plants [Lotus japonicas L. [Solanum lycopersicum L. [A. thaliana and Oryza sativa L. it has been postulated that SLs may also participate in plant responses to wounding, cold stress or flooding and the cross-talk between SLs and other class of hormones was predicted [Strigolactones (SLs) are a class of plant hormones first identified as such in 2008 as shoot branching factors ,2. Befortivum L. , and alstivum L. . On top tivum L. ,10). Thee plants ,12. Addinicas L.  and Solasicum L. ,15 confisicum L. . Neverthredicted . Recentlredicted .trans-β-carotene through a carotenoid isomerase and two carotenoid cleavage dioxygenases [SLs are biosynthesized in roots and transported to the shoot via SL transporter PLEIOTROPIC DRUG RESISTANCE 1 (PDR1) , but theygenases . Carlactygenases , the maiygenases . All knoygenases . Furtherygenases ,26.max2 phenotype are more KAR- than SL-dependent [5DS and GR24ent-5DS, that may differently influence both SL and KAR signalling pathways [max2 mutants and/or racGR24 have to be critically interpreted, since the observed phenotype might be caused by stimulation or disorder in the KAR signalling pathway. The prevailing view is that application of SL biosynthesis mutants or mutants with disorders in SL receptor should become the gold standard in SL studies [max2 mutants instead of plants with a proven mutation in SL receptor D14 (DWARF14).In recent years, SL perception and signalling including the complete SL signal transduction pathway have been unravelled . SLs areependent ,33. Evenpathways . This me studies . The preA. thaliana provided the first evidences that SLs may be involved in the control of root system architecture. Under optimal growth conditions mutants of SL biosynthesis  and SL signalling (max2-1) developed more lateral roots (LRs) compared to wild-type plants [max2 signalling mutant in an MAX2-independet manner [Hordeum vulgare L.) the SL signalling mutant hvd14.d also displayed a higher density of LRs but showed no differences in LR length compared to the wild-type [hvd14.d mutant [Lotus japonicus L. where lines silenced for one of the SL biosynthesis genes (LjCCD7) showed more LRs [Medicago truncatula Gaertner (Gaertn.) where racGR24 treatment of wild-type plants resulted in lower LR density [d10) or SL signalling (d14) mutants possessed similar numbers of LRs as wild-type [Studies on e plants . Treatmet manner ,36. It tt manner . In barlild-type . Treatmed mutant . Similarmore LRs , and in  density . In riceild-type .d14 mutants in rice and barley, however, indicated that a higher number of LRs was only present in the barley mutant [While it, thus, appeared that racGR24 had an overall inhibitory effect of LR formation in all wild-type plants tested, analysis of y mutant ,41. Thesy mutant , whereasy mutant , young rSolanum lycopersicon L., it did promote cell elongation during auxin (IAA) treatment, thus reversing the suppressive effect of IAA [A. thaliana grown under optimal conditions primary root (PR) length of SL mutants and wild-type plants were similar, but a positive effect of racGR24 treatment was present under carbohydrate starvation [hvd14.d mutant were distinctly shorter than those of the wild-type [LjCCD7 of L. japonicus had longer PRs, suggesting that in this species SLs suppress PR growth [Reports on SL effect on root length are inconsistent . While rt of IAA . In A. tarvation . In ricearvation , but in ild-type . In bothild-type ,43. In cR growth . Accordid10, whereas no effect was observed in the SL signalling mutant d14. Although the root meristem of the mutants d10 and d14 is shorter than the one in wild-type, the length of the root cells in the mature zone of the roots is similar. This indicates that SLs affects CR elongation by stimulating cell divisions [The role of SLs in CR development has so far only been investigated in rice . Althougivisions .d10, but not in the SL signalling mutant d3 [A. thaliana and pea, however, SL mutants had fewer ARs, suggesting a negative role of SLs on LR formation [The role of SLs in adventitious root (AR) formation is also far from clear . At matuutant d3 . In A. tormation . Treatmeormation .In many aspects of root development, the role of SLs remains unclear and inconsistent data for different species have been published . It has A. thaliana the inhibition of PR growth is accompanied by an increase in LR density and length [A. thaliana grown under optimal growth conditions SLs reduce LR abundancy, the opposite was observed under P starvation where treatment with racGR24 promote outgrowth of LR primordia [D10, D17 and D27. At the same time expression of SL signalling genes D3 and D14 was decreased, probably due to negative feedback regulation [d3, d10 and d27 are less sensitive to both N and P starvation conditions than wild-type plants. In the presence of racGR24, however, the sensitivity of SL biosynthesis mutants to N and P deficiency became similar to that observed in wild-type plants, whereas SL signalling mutants showed no such increase in sensitivity [SLs are involved in plant response to nutrient stress, since elevated SL production and exudations were observed in different species under phosphorus (P) and nitrogen (N) starvation conditions . Plants d length . In othed length . Whereasrimordia . A similgulation . Concernsitivity . In the sitivity  SR growtsitivity .A. thaliana under optimal conditions, but an opposite effect was observed under P starvation [These data prove that the modification of root architecture in response to nutrient stress is SL dependent. Furthermore, SLs appear to play a somewhat different role under nutrient deficiency than under optimal growth conditions . For exaarvation .d3 and d10 showed a similar increase in NO in root tip meristems but no root elongation [d14 mutant. This shows that elongation of rice SRs in response to N and P starvation is induced by NO, which in turn depends on degradation of the SL repressor [Sanz et al. realized that under P and N deficiency, SLs act together with nitric oxide (NO) in regulating root elongation . Furtherongation . NO induepressor . It is nepressor .Sorghum bicolor L. under P and N deficiency revealed that the production of 5-deoxystrigol, one of the major SLs identified in this species, was almost 30 times higher during the response to nutrient stress conditions than in the control plants [Calendula officinalis L., Triticum aestivum L., Solanum lycopersicum L., rice, Trifolium pretense or Pisum sativum L. . It wasiewed by . Whereasiewed by . It was iewed by . Finallyiewed by ,55.Presented results clearly shown that SLs. are involved in different aspect of plant adaptation to survive under nutrient deficiency conditions. They do not only regulate the root architecture, but also support different strategies to enhance uptake of nutrients and survive the time when nutrient availability is limited.A. thaliana roots racGR24 treatment causes a decrease and/or altered distribution of the auxin efflux carriers PIN-FORMED1 (PIN1), PIN3, and PIN7 in PRs [SLs regulate root system architecture via interactions with other hormones, such as IAA and cytokinins (CKs). In 7 in PRs . RacGR247 in PRs . A simil7 in PRs . Treatme7 in PRs .PIN7 reduced the root sensitivity to racGR24, and additionally mutant pin1 is more sensitive to SLs and forms fewer LRs in the presence of racGR24 [A detailed analysis of PIN1 localization after racGR24 treatment failed to confirm the previously described effect . However racGR24 . Althoug racGR24 .Since both, SLs and CKs, play a negative role in LR elongation, a cross talk between these two classes of hormones has been postulated. Analysis of CK signalling mutants indicated that mutations in the CK receptor—ARABIDOPSIS HISTIDINE KINASE3 (AHK3)—resulted in insensitivity to racGR24 treatment. Plants with mutations in the CK receptors AHK2 and AHK4, still respond to racGR24 with a reduction in LR density . AnalogoA. thaliana it acts as a negative regulator of AR formation, similar to SLs. While A. thaliana SL mutants are sensitive to treatment with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, mutants in ethylene biosynthesis and signalling are sensitive to racGR24 treatment [The fourth class of hormones involved in regulating root development is ethylene. In reatment . When boreatment .max2 in the presence or absence of racGR24 revealed a group of metabolites whose production or accumulation is SLs dependent [Metabolome analysis in wild-type and ependent . The majependent  and addiependent  and abscependent .5DS and GR24ent-5DS recognized by the SL receptor D14 and KAR receptor KAI2, respectively increased, in both cases, the production of flavonols. In the single d14 and kai2 mutants flavonols were still present [kai2 and d14 mutants may shed new light on the action of both hormones on plant growth and development.Treatment with GR24 present , suggestmax2 mutants which apart for SL signalling, are also involved in KAR signalling. A better alternative would be the application of the specific SL signalling mutant dwarf (d14) which is identified in multiple species, including A. thaliana and rice. Finally, for SL treatment experiments only the GR245DS or pure naturally occurring SLs should be employed. Such studies should be supplemented by detailed investigations of the molecular cross talk between SLs and other main players in root development: IAA or CKs.SLs are best known for their role in the regulation of root system architecture. A detailed analysis of the literature brought to light several inconsistencies regarding the putative function of SLs . The sim


The addition of alkali-resistant glass fiber to concrete effectively suppresses the damage evolution such as microcrack initiation, expansion, and nucleation and inhibits the development and penetration of microcracks, which is very important for the long-term stability and safety of concrete structures. We conducted indoor flat tensile tests to determine the occurrence and development of cracks in alkali-resistant glass fiber reinforced concrete (AR-GFRC). The composite material theory and Krajcinovic vector damage theory were used to correct the quantitative expressions of the fiber discontinuity and the elastic modulus of the concrete. The Weibull distribution function was used and an equation describing the damage evolution of the AR-GFRC was derived. The constitutive equation was validated using numerical parameter calculations based on the elastic modulus, the fiber content, and a performance test of polypropylene fiber. The results showed that the tensile strength and peak strength of the specimen were highest at a concrete fiber content of 1%. The changes in the macroscopic stress–strain curve of the AR-GFRC were determined and characterized by the model. The results of this study provide theoretical support and reference data to ensure safety and reliability for practical concrete engineering. At present, concrete is one of the most widely used and indispensable engineering materials for large-scale infrastructure construction projects such as tunnels, roads, water conservancy projects, and marine engineering projects . HoweverAlkali-resistant glass fiber reinforced concrete (AR-GFRC) is a composite material composed of cement slurry, or concrete, as the base material and AR-glass fiber as the reinforcing material. Several studies have been conducted on cracks and aging in AR-GFRC. Soranakom and Bakhshi  investigMany problems associated with crack development and aging in concrete have not been addressed in recent research studies and require further investigation. Crack occurrence and propagation are nonlinear types of behavior at the macroscopic scale, as has been demonstrated in previous research ,7,9. TheIn this study, the composite material theory and statistical damage theory were applied and the concrete discontinuity was investigated by revising the parameters associated with the concrete discontinuity and the elastic modulus. The Weibull distribution probability density function was used to derive an equation describing the statistical damage evolution of the AR-GFRC and a numerical feature method was used to determine the statistical parameters of the model. Subsequently, the proposed model was extended and validated based on the composite material’s elastic modulus, the fiber content, and a performance test of similar material to ascertain the applicability of the model and meet the engineering needs.In order to determine the effect of the AR-glass fibers on the mechanical properties of the concrete, Anti-Crak®HD/alkali-resistant glass fiber and Anti-Crak®HP/alkali-resistant glass fiber were selected as reinforcing materials in the uniaxial tensile test . The mecThe concrete matrix is composed of cement, sand, gravel, mineral powder, and admixture in certain proportions. In order to achieve the best performance and mechanical properties of the high-performance concrete, the mix ratio was obtained by using the ‘Full Calculation Method’, described by Mehta and Aitcin .The concrete matrix contained the following materials in certain proportions: P.O 42.5 ordinary Portland cement, Wenhe middle sand from Tai’an (China), 5–20 mm continuous graded gravel, S95 grade slag mineral powder, and SM-IV polycarboxylic acid superplasticizer. The concrete specimens’ strength grade in the tensile test was C30. The specimen preparation was conducted in accordance with the laboratory specifications. The dimensions of the flat tensile test specimens were 600 mm × 600 mm × 60 mm and the specimen die was made of channel steel with dimensions of 60 mm × 40 mm × 60 mm. The mix ratios of the different fiber contents and lengths are shown in An HJW-60 concrete mixer , HZJ concrete shaking table, HBY-40A concrete standard curing box, and YJ-22 electric measuring instrument  were used in the tensile test. Three test specimens were selected for each group and the test results were accurate to 0.1 MPa during the test . The tesFor the plain concrete, once a crack appeared, the ultimate tensile strength was reached; the crack propagated until it penetrated the entire fault surface, as shown in As shown in In order to investigate the effect of the fiber content on the tensile strength of the concrete, HD12 and HP12 AR-glass fiber were added to the concrete matrix. The strength grade was C30 and the volume content was 0%, 0.5%, 1%, and 1.5%. Using the control variable method, the tensile test of fiber concrete with different contents was carried out, and the tensile stress–strain curve of the AR-GFRC is shown in In order to investigate the reinforcement and failure mechanism of the AR-GFRC, a constitutive equation of the damage evolution of the AR-GFRC is derived. At present, research on the damage of fiber reinforced concrete is mostly based on the composite material theory and the fiber spacing theory. However, the latter theory was put forward based on linear elastic fracture mechanics and is based on empirical results of strengthening tests of fiber reinforced concrete. The theoretical results are in good agreement with the experimental results for steel fiber reinforced concrete but there are large differences for AR-GFRC. Therefore, the damage constitutive model of the AR-GFRC is developed based on the composite material theory in this section.(1)The concrete matrix and AR-glass fiber are both isotropic linear elastic materials.(2)The fibers stress direction and the distribution are parallel to the external tension load.(3)When tension deformation occurs in the concrete, the deformation is the same for the fiber and the concrete and no relative sliding or dislocation occurs. The stress of the concrete is shown in In the composite material theory, the composite material is regarded as a two-phase matrix; the fiber is one phase and the matrix is the other phase. The mechanical properties of a composite material are affected by the matrix properties and fiber properties. In order to develop the constitutive model, the basic assumptions are as follows:u is the displacement in the direction of the x axis, σx is the applied stress and fcE is the elastic modulus. Equation (1) can be expressed as:Based on the mechanical equilibrium equation and assumptions (1), (2), and (3), according to Saint Venant’s Principle, Equation (1) can be expressed as:x = 0, x = l:fc is the stress of the micro-body inside the material, as shown in fc, σf and σm are the stress of alkali-resistant glass fiber composites, glass fiber and matrix, and EV is the influence parameter of the volume modulus on the elastic modulus.It can be obtained by boundary conditions fl and taking the average value is λ is a proportional parameter, k is a shape parameter and fl and fd are the fiber length and fiber diameter, τ is the average value of the bonding stress between the fibers and the concrete matrix, eη is the fiber length mean coefficient obtained by Weibull function and The AR-GFRC has a discontinuous and non-penetrating matrix. Therefore, assumption (2) must be modified. Previous research results have demonstrated that the continuous distribution of concrete fibers has a Weibull distribution. When calculating based on section method, the bonding length of the fiber is considered as 0~0.5τ between the fibers and matrix is proportional to the tensile strength of the AR-GFRC:fη is the correlation coefficient of the matrix cohesive properties; the value depends on the fiber type, diameter, length, surface shape, and other factors. Equation (8) is substituted into Equation (7):It is assumed that the cohesion fcE is the first derivative of σfc to fcε. The derivative of Equation (9) is obtained:The composite elastic modulus γη is the correction coefficient of the AR-glass fiber elastic modulus in the composite and α is the length–diameter ratio of the fibers, that is α = fl/fd.In order to simplify Equation (9), we define D is the initial crack damage in the material. C1 and C2 are material constants. For AR-GFRC, C1 = 3.5–6, C2 = 0.35–0.7.The AR-GFRC uniaxial tension can be divided into the undamaged and damaged evolution stage, in which the undamaged stage obeys Hooke’s law. For the damaged evolution phase, the uniaxial tension constitutive equation of the concrete is obtained based on the Krajcinovic Vector Damage Theory ,22 and tBased on assumption (3), the microcrack growth mainly occurs in the plane perpendicular to the tensile axis. According to the incremental formula, it can be concluded that:That is:The hyperbola method is used to simplify the damage surface based on the Mohr–Coulomb criterion under uniaxial tension. At this time, the generated strain is the same as the damage evolution value. That is:Equation (16) is substituted into Equation (15) and the definite integral is obtained:f(σij) is a stress function and k is related to the material parameters.The initiation, development, and fusion of cracks in the AR-GFRC occur under tension. Fiber reinforced concrete is generally regarded as a series of defective micro-units in the statistical damage constitutive model . The micx = (σij) and p(x) is the probability density distribution function of the micro unit, N is the total number of micro-units and Np(x)dx is the number of microelements destroyed in any interval . The damage variables of the AR-GFRC can be expressed as the ratio of the number of damaged micro units and the number of material micro-units. That is:To ensure that p(x) is expressed as:m and x0 are the statistical parameters of the Weibull distribution.The development of damage or microcracks is not irregular and randomly distributed. Due to the influence of fracture energy and the difference in the elastic modulus of fiber and the concrete matrix, micro-crack development tends to be directional in the uncoordinated regions of deformation of materials. For the convenience of calculation, the contact surface position of the concrete matrix and fiber is equivalent to the distribution position of fiber. The deformation characteristics of the concrete, rock, and other materials and the microscopic heterogeneity of the mechanical properties of quasi-brittle materials follow the Weibull distribution ,25. TherD:Equation (20) is substituted into Equation (19) to obtain the damage variable c is the cohesive force of the concrete matrix and φ is the internal friction angle. According to the experimental mix ratio, c is 3.18 MPa and φ is 54.9°. Equations (15)–(17) and (21) are substituted into Equation (14):The strength of the micro-unit can be expressed based on the strength failure criterion of the Mohr–Coulomb micro unit:That is:Equation (24) can be simplified as follows:By defining the integral of Equation (25), we obtain:fS is the area ratio of the fibers on the damaged surface, fε is the strain of the broken fibers, i.e., the elongation at the breakpoint. The statistical damage constitutive model of the AR-GFRC under tension can be obtained from Equation (13) and Equation (27).When the AR-GFRC is damaged and destroyed, the tensile capacity of the concrete matrix will be lost. However, the tensile crack resistance on the damaged fracture surface persists until the fibers are pulled out or are broken ,27. TherThe damage factor equation is:fl, fd, mE, fE, C1, and C2, are determined by the characteristics of the AR-GFRC and can be obtained by tests. The others are statistical parameters, such as the two Weibull distribution parameters m and x0, which need to be determined based on the concrete tension and compression test curves. At present, the methods to determine the statistical parameters include linear fitting [S are the average strength and standard deviation of the AR-GFRC, respectively. That is:Among the tensile constitutive model parameters of the AR-GFRC, the mechanical parameters of the concrete, such as  fitting , the pea fitting ,30, the  fitting , and non fitting ,33. In tm can be determined by Equation (31) and the shape parameter x0 can be obtained by using x0 in Equation (30).The scale parameter The elastic modulus of the AR-GFRC consists of the elastic moduli of the undamaged part and damaged part; the test value of the elastic modulus of the AR-GFRC can be obtained from the concrete tensile test data. The elastic modulus of the proposed constitutive model can be calculated using Equation (12) and is then compared with the elastic modulus obtained from the test; this provides parameter information for the theoretical stress–strain curve. The experimental and constitutive theoretical stress–strain curve fitting is shown in The experimental and theoretical stress–strain curves before the damage evolution stage are well fitted. The experimental results of the elastic modulus of the AR-GFRC are close to the model values, which validates the uniaxial tensile constitutive model. The results demonstrate that the derivation process of the constitutive model is accurate and reasonable. The results in The tensile test data of the HD and HP concrete with different fiber contents are used to verify the damage constitutive model of the AR-GFRC. In order to determine several test parameters in the constitutive model, six groups of HD and HP concrete test datasets with different fiber contents after 28 d of standard curing are used for the verification. The Poisson ratio of the concrete specimens was 0.3, the elastic modulus was the theoretical elastic modulus ) is close to the elastic modulus value obtained by the test. The trend before the damage evolution stage is consistent and a good fit was obtained. The fiber contents were 6% in group A9 and the verification method was the same as that described in The results indicate that the stress–strain evolution of the concrete with the different fiber contents can be accurately described by the proposed damage constitutive model of the AR-GFRC. The theoretical constitutive curve and the experimental data curve fit well before the peak and the peak strength and peak point values are similar. In addition, the range of fiber content used for the model verification was large and there are few differences in the fracture surface, which results in a small difference in the maximum tensile strength between the experimental and theoretical results. Furthermore, the theoretical and experimental stress–strain curves are in good agreement after the peak. This demonstrates that the proposed statistical damage constitutive model of the fiber reinforced concrete is well suited for characterizing the stress–strain curve of the AR-GFRC using the tensile test data of the PP fibers.In summary, the statistical damage constitutive model of the AR-GFRC is based on the composite material theory and Krajcinovic vector damage theory. It is assumed that the concrete consists of a series of isotropic elastic microarray elements and that the probability distribution of the micro-element failure follows a Weibull distribution. However, in practical applications, the interface between the concrete matrix and fiber is not isotropic and the derived constitutive equation may not describe the actual conditions accurately. Yet, lateral damage in concrete does not occur in an indoor uniaxial tension test. Therefore, the actual stress–strain of the concrete can be determined by the proposed constitutive model in the simplest form. Different fiber contents and the elastic modulus of the composite materials can be used to determine the meso-damage evolution and failure mechanism of the AR-GFRC and of the concrete in practical engineering applications. The results provide important practical and reference data to ensure safety and reliability for concrete engineering.(1)Indoor flat tensile tests of AR-GFRC were conducted and the macro-crack failure modes of the plain concrete and AR-GFRC specimens were analyzed to determine the occurrence and development of cracks in the material. The peak strength of different types of concrete under standard curing was quantitatively analyzed to determine the influence of the fiber content on the tensile strength of the concrete. It was determined that the tensile strength and the peak strength were highest at a fiber content of 1%.(2)The composite material theory and Krajcinovic vector damage theory were applied to modify the equations related to the fiber discontinuity and elastic modulus. The Weibull distribution function was used to derive the equation of the elastic modulus of the fiber reinforced concrete composite and the statistical damage constitutive model of the AR-GFRC was developed. The statistical parameters of the model were determined using the numerical feature method.(3)The constitutive equation was validated based on the elastic modulus and the different fiber contents obtained from indoor uniaxial tensile tests. The validation results indicated a good fit of the theoretical and experimental results of the elastic undamaged stage and damage stage with a fitting degree larger than 0.93. Tensile test data of PP fibers made of similar materials were used to extend and validate the proposed constitutive model using the same validation method. The results showed a fitting degree larger than 0.92 for the theoretical and experimental stress–strain curve before the peak value. The statistical damage constitutive model of the AR-GFRC provides reference data and theoretical support to ensure the safety and stability of concrete structures.


Substantial pressure to reduce antibiotic use has necessitated the development of antibiotic alternatives. However, relatively little consideration has been given to the development of resistance to these alternatives.Whether we come up with antibiotic alternatives that are bacteriocidal or inhibitory, bacteria will continue to adapt and evolve.Some antibiotic alternatives support the development of antibiotic resistance necessitating caution.There are opportunities to optimize antibiotic alternative effectiveness as well as to minimize the development of resistance mechanisms.With the growing concern of antibiotic resistance , there hCampylobacter jejuni  system as a pseudoimmune system, or the abortive infection system to kill infected cells before the phage can spread , Zinc (Zn2+), and Silver (Ag+), and nonmetal elements, such as Iodine (I2), have been used in animal production for their broad-spectrum antibacterial activity and low generation of resistance  with a wolf in sheep’s clothing .Pig image: many antimicrobial alternatives target the early post-weaning piglet.Polyphenols: polyphenolic compounds found in plant products, such as these pea seed coats, have strong antibacterial activity.


Ruvheneko Programme by the people of Chirumhanzu helped in mitigating on the impact of HIV and AIDS in the rural sphere. The paper analyses how the community of Chirumhanzu successfully engaged each other to the extent of coming up with such a vibrant programme. This is raised against the backdrop of failure usually associated with HIV and AIDS engagement projects. The study made use of field interviews and focus group discussions as data collection instruments. Participants were purposively selected on the basis of their knowledge and participation in the establishment and activities of Ruvheneko Programme. Selected were 5 St Theresa’s Hospital Staff, 10 Roman Catholic Church members of which, 5 were from the St Anna’s woman prayer group and 5 men from St Joseph’s men prayer group, 1 village head and 2 elders from the same nearby village constituted key informants. Complementing the use of interviews and focus group discussions was the analysis of secondary data sources on HIV and AIDS in Zimbabwe as well as the Ruvheneko Programme. To understand the collective role of various sectors of the community in establishing Ruvheneko Programme, the paper derives insights from the perspective of social capital theory and its notion of commonality to strengthen communities. Findings from the study show that, unlike other HIV and AIDS programmes that are exported from the urban to the rural areas, Ruvheneko Programme demonstrates a grassroots-level response to HIV and AIDS. Again, social cohesion fostered by aspects such as religiosity, cultural ethos of Ubuntu, and a consultative approach played a key role in unifying people towards fighting HIV and AIDS in Rural Chirumhanzu.Since reports of the first incidence of the HIV virus in Zimbabwe in 1985, the epidemic has negatively impacted on every facet of human security. Rural areas, by virtue of being the periphery and constrained in terms of resources and health care provision, bear the brunt of the epidemic. In light of the above background, this paper examined how the establishment of  Madzimai Enzanga are also renowned for their involvement in helping the poor and sick with prayers, food stuffs, and clothes, even before the HIV and AIDS era. They started providing palliative and spiritual care to the infected and affected by helping in such tasks as bathing the sick, doing laundry, praying for the sick, watering gardens, weeding in the sick person’s agricultural fields as well as providing subsistence food stuffs. However, the increase in the number of HIV and AIDS related deaths, with an average of 15 people dying every month from AIDS related illnesses as well as high records of an average of 140 HIV and AIDS related cases per day, compelled the community, RCC, and the hospital authorities to join hands in the fight against HIV and AIDS . They established what came to be known as the St Theresa’s HBC project in 1995 and this marked the origin of Community Home-Based Care (CHBC), though informal at this stage. An interest to pursue research on the Ruvheneko Programme was triggered by the publicity it received as a model for HIV and AIDS programme in a resource constrained rural setting . This helped in providing food to less privileged families with food from the common granary which all village members worked on. This mindset is supported by Putnam  has seen gold-panning becoming one of the major activities attracting unemployed people from the surrounding rural communities. Many unemployed people in Chirumanzi have been trapped in gold-panning as an economic activity given that the area is overcrowded, rocky and dry, rendering it agriculturally unproductive. At the time that Ruvheneko was established, the discovery of gold saw many people flocking to the area for gold-mining. The life-style of the illegal gold-miners, popularly known in Zimbabwe as Nzanga yaMbuya Anna in the local parlance and 5 men from St Joseph’s men prayer group also known locally as Nzanga yaJosefa), traditional leadership (1 village headman from the nearby Mahaso village and 2 elders from the same village). This sample was chosen for practical reasons, especially to ensure easy management of both the participants and the collection of in-depth data. In general, 18 interviews were conducted with the objective to get a detailed and rich narrative on the phenomenon being investigated. The men and women from the prayer groups were selected from various villages served by Ruvheneko Programme. Choosing participants from diverse village settings helped to improve on the trustworthiness of the research findings as opposed to choosing participants from one locality. All the participants were purposively selected on the basis of their knowledge about the establishment of Ruvheneko, with the exception of Mahaso village which was chosen on the basis of accessibility and proximity to the hospital.St Theresa Hospital is one of the oldest health care Mission centres in Zimbabwe and is renowned for servicing resource constrained rural areas. The research sample consisted of 5 St Theresa’s Hospital Staff, 10 church members  except for Dr. Stoughton only, which is a real name because his name appears in the secondary sources of data.4.4.1.Findings from the interviews with the hospital staff revealed that what is now Ruvheneko Programme should be understood in the context of the pioneering project, the Chirumhanzu Home Based-Care Project which started in 1994. Mrs Moyana (pseudonym) none of the senior hospital official narrated that, ‘the project was merely an initiative by hospital health personnel, Dominican Sisters and expatriate Doctors who tried to address the challenge of increasing HIV and AIDS patients in the Hospital.’ The idea was also to help family members cope with the challenge of HIV and AIDS while working with volunteer Care-Givers who are supervised by professional nurses. The Home Based-Care approach adopted a comprehensive framework which included providing socio-psycho support to the infected and affected.As presented in the St Theresa’s Hospital Annual Report , ‘family4.2.The interviews with most of the hospital staff revealed that ‘community mobilisation was a key factor in mobilising the people of Chirumhanzu towards adopting a unified stance in the fight against HIV and AIDS.’ Mobilisation was therefore achieved through CHBC visits to several rural villages and households. The understanding at this point was that forming an effective partnership between the ‘users’ and ‘providers’ was the only path towards grassroots responses to the devastating impact of HIV and AIDS in the community. It emerged that the CHBC project was a precursor to the establishment of Ruvheneko in the sense that it marked the first hospital initiative where Care Givers could visit the sick in the comfort of their homes. The idea was to reduce stigma through teaching people on how to cope with the HIV and AIDS problem as well as supporting the infected psycho-socially, spiritually, medically, physically, and materially. As pointed out by Cephas (pseudonym) one of the Ruvheneko Programme senior officials, ‘CHBC was meant for capacity building in order to strengthen local community responses and understanding of the HIV and AIDS epidemic as well as encouraging participation.’ Community mobilisation was accomplished through various HIV and AIDS awareness campaigns in the form of poems, drama, and several visits to different communities serviced by the hospital. The activities carried out during the households and village visits included, teaching people about the impact of HIV and AIDS on individuals, friends and family; behaviour change; traditional practices and cultural norms which fuel the spread of HIV and AIDS; treatment of orphans and vulnerable children; as well as safer sex negotiation skills. It was reported that these mobilisation initiatives did not only attract community participation, but helped to break the silence about HIV and AIDS which indeed was not an easy topic to talk about openly because of the associated stigma and discrimination. Community mobilisation heralded a collaborative effort in the fight against stigma and discrimination that had exacerbated the raging virus. From the interviews with the hospital staff, it emerged that engaging the community through their leaders (who are the custodians of the people) helped to establish report and communication link between health professionals and the end users who are in this case the community.4.3.Mai Mukuru (St Anne’s sect group leader), is a religious obligation, and, to phrase it in her own words, … kutenda kusina mabasa kwakafa mwanangu. This translated in English means that faith without actions is dead my child. The point being conveyed in this context is that, acts of charity are considered as good deeds and a reflection of true faith, and it forms part of Christian ethos to do humanitarian responsibilities. This also conveys the message that Christians have a moral obligation to show compassion, love and integrity both individually and communally, and this is what the Ruvheneko VCGs and primary caregivers strive to achieve. In line with religious ethos, it also emerged that one key strategy that galvanised the initiative to establish Ruvheneko is the formation of the Chirumhazu Church Leaders Association (CCLA) in 2003. The CCLA is an interdenominational arrangement of various church leaders in the area meant to find solutions to the HIV and AIDS problem. According to Sekuru Murehwa (pseudonym) from the men’s prayer group, Nzanga YaJosefa,utachiwana hwe HIV/AIDS hauzivi mutsauko wemasvondo uye kana vanhu vachidanana, kashoma kufunga nezvesangano. Izvi ndizvo zvinoreva kuti panoda kubatana kwedzisvondo mukurwisa chirwere ichi … .… Through these religious ethos, other churches came to appreciate the need for proactive engagement in HIV and AIDS matters and it helped to break the perceptions about the HIV and AIDS epidemic as well as condom usage which most churches believed was responsible for promoting promiscuity.In addition to community mobilisation, another finding is that focus group discussions and interviews revealed how women and men’s prayer groups utilised biblical ethos in persuading encouraging fellow community members to participate in HIV and AIDS projects/affairs. The initiative taken by the women’s prayer group in taking care of the sick, according to 4.4.(sabhuku). The headman gave an example of the idiom which fosters cooperation among the Shona people which says … chaona hama hachisekanwi (do not laugh when your neighbour is in trouble). In the traditional parlance, the idiom was and is used to discourage the community from spiting or laughing at those who are poor or experiencing problems. The idiom was later adopted in order to warn people against laughing and discriminating against People Living with HIV and AIDS (PLWHA). According to the Mahaso village headman, … dama nderokuti seka urema wafa … . In the light of these rich cultural precepts, helping others is thus seen as some kind of social investment since there is hope that community members will reciprocate the good deeds should one need the same help in future. These cultural and religious belief systems infused a sense of community belonging which encouraged many to participate in the establishment of the Ruvheneko Programme.Complementing religious initiatives was also the aspect of volunteerism embedded in the Shona cultural and beliefs practices according to the Mahaso village headman gunwe rimwe haritswanyi inda … which when directly translated means that one finger cannot kill lice. What emerged from the interviews with the village elders is that fighting HIV and AIDS cannot be separated from other traditional practices that discourage individualism in addressing social problems. It can therefore be argued that a blend of religious, social and cultural values became the foundation upon which community engagement and participation was fostered. In retrospect, the Ruvheneko programme can thus be construed as one of those home-grown solutions to rural community problems which had developed self-sustainable approaches to HIV and AIDS.From the interviews with the two other village elders, Baba Garapo and Baba Muchihwa (pseudonyms), the formation of Ruvheneko also benefited from the Shona idiom … 4.5.Ruponeso (Bringing back life), Rusununguko (Freedom), Ruvheneko (meaning light) as it is understood in the Shona language. Amongst the suggested names, Ruvheneko was found to be the most appealing. Etymologically, Ruvheneko in Shona language designates ‘light’, ‘giving light’ or ‘brightness’.Findings from the interviews and focus group discussions with various participants acknowledged the role of the April 2003 stakeholder meeting involving the Ministry of Health and Child Welfare (MoHCW); CCLA representatives; chiefs and headmen; the Ministry of Education (MoE), represented by school headmasters; and PACT Zimbabwe, representing the funders – Canadian International Development Agency (CIDA) and Swedish International Development Agency (SIDA). A principal from the local St Josephs’ school, Mr Mhara (pseudonym) narrated that ‘through the guidance of hospital leadership, the stakeholders at the meeting agreed to transform the CHBC from a project to a programme.’ This also involved choosing a new name for the CHBC and several names emerged from the consultations with the community members such as Mai Mukuru, Mbuya Hwande (pseudonym) the name Ruvheneko helped to address derogatory labels such as ‘Vanhu veAIDS’, which means AIDS people, which were attached to the HIV and AIDS patients and those involved in HIV and AIDS projects. Such derogatory labels caused stigma, and most of the village care givers involved in the CHBC who were not infected were not comfortable with the name Vanhu veAIDS. More importantly, such derogatory labels are common talks at beerhalls, community gatherings and usually emerge from carefree people who do not sympathise or accommodate those infected or affected by HIV and AIDS. It can therefore be argued that the name Ruvheneko helped to address these concerns as it promised hope and a sense of collectivity among various stakeholders. Both the infected and affected could now work well without any negative connotation as expressed by one of the community leaders, according to the interview with Mr Gore Following the naming of the programme, stakeholders made it clear that the main objective of Ruvheneko is to reduce stigma surrounding HIV and AIDS by giving quality care to patients and to provide psycho-social support to the infected and affected.According to 4.6.the decision to involve men in HIV and AIDS matters stemmed from the realisation that HIV and AIDS knows no gender barriers and that leaving men out was going to complicate things since most of them were not going to allow their wives to participate in HIV and AIDS programmes. Moreover, most men in rural areas are involved in risk sexual behaviours and they end up infecting their wives and we realised that involving them brings a positive change.In essence, Ruvheneko Programme brought a paradigm shift to the African traditional practices of relegating household chores like fetching water and caring for the sick to women and girl children only. This observation is in line with Familusi’s (An interesting finding from the establishment of the Ruvheneko Programme is the gendered dimension. This is reflected in the positive participation of men in the activities leading to establishment of Ruvheneko. In an interview with Mai Gono (pseudonym), one of the Hospital staff, it emerged thatmilusi’s  analysis5.The aim of the study was to examine the initiatives that were put in place in establishing the Ruvheneko Programme and this was discussed in the context of the fact that Ruvheneko has been cited in newspapers and academic writings as a model of response to the human security threats posed by HIV and AIDS in resource constrained rural settings in Zimbabwe CDC, . RuvheneAn interesting finding regarding all the initiatives towards the establishment of Ruvheneko is that the severity of HIV and AIDS in Chirumhanzu created some kind of fear of the unknown to the extent that members felt obliged to be part of the programme. This resonates with Rodriguez-Garcia’s  model ofThere is also an interesting dimension regarding the role of the Church in the founding of Ruvheneko Programme. Literature shows that the church in Zimbabwe was slow to respond to the impact of HIV and AIDS and this was premised on the belief that the epidemic was punishment from God (Clifford, In addition to the role of the church, findings point to the important role of religious ethos in the establishment of Ruvheneko. There is a religious meaning ascribed to the name wherein the former St Theresa’s Hospital and patron for Ruvheneko, Dr. Stoughton, linked the name Ruvheneko to the biblical context in John 8 verse 1 2 which reads: ‘I am the light of the world’ (Mission Doctors Association Report, Heal the Sick, Ubuntu, translated in Shona as unhu or hunhu, meaning a responsible human being (Kaseke & Dhemba Ubuntu, thus sees homes shunning the individualistic or inward-looking families, to ones based on communalism (Kaseke & Dhemba The element of volunteerism which is also core to the establishment of Ruvheneko Programme resonates with African traditional belief systems. Community participation and volunteerism in Chirumhanzu is perceived as a duty enshrined in cultural and moral values of the community. It is regarded as a sign of Effective community mobilisation is one initiative which played a pivotal role in engaging the community and the whole notion of community engagement can be understood in the context of the discourse of ‘participatory’ approach to development’ (Chambers, It is therefore justifiable to assert that the establishment of Ruvheneko can be attributed to effective community engagement which allowed community participation and involvement. This manifested for example in the selection of the programme name after a wide consultation and debate with community members during the stakeholders meeting. The fact that the community members were actively involved in the selection of the programme name fostered a sense of ownership of the programme. In addition, experiences from other projects like Mashambanzou Care Trust partner organisations engaged communities through participation, they were not directly involved in the conceptualisation and planning of the projects. As such, community involvement was mainly limited to implementation and interventions like the OVC and HBC relying heavily on voluntary skills. Besides volunteer skills, community resource mobilisation has been marginal across the evaluated projects. Other similar projects like the one in Chimanimani show the crisis of involvement as a major setback to achieving success and sustainability in rural initiated HIV and AIDS programmes. In the case of Chimanimani, a study by Madzingira, Muhwava, and Mapfumo  reveals Lastly, another finding regarding how Ruvheneko managed to appeal to the communities is that the idea of using poems and drama in raising awareness concurs with the notion of ‘edutainment’ raised by Goldstein, Usdin, Scheepers and Japhet  in their6.The study has demonstrated that the severity of the human security threats posed by the scourge of HIV and AIDS led to the creation of an alliance between the church, hospital, and the community as a home-grown solution to the problem of HIV and AIDS in the Chirumhanzu rural area. It emerged that volunteerism which characterised community participation emanated from biblical, cultural and traditional ethos which contributed positively towards solving community problems, including HIV and AIDS. This article demonstrated that all the initiatives adopted in the establishment of the Ruvheneko Programme show the importance of a holistic approach in mitigating the impact of HIV and AIDS in resource constrained rural settings. The paper concludes that a holistic approach involving effective community mobilisation, religious and cultural ethos as well as the gendered approach, played a pivotal role in making Ruvheneko a unique rural initiative in responding to the human security threats posed by HIV and AIDS.


Dental infections are multimicrobial in origin with their etiological factors involving a combination of Gram-positive, Gram-negative, facultative anaerobes, and obligate anaerobic bacteria. Thus, antibiotics and analgesics account for a great majority of medicines prescribed by the dental surgeons. Inappropriate prescription of antibiotics by health care professionals has become a worldwide issue nowadays.The purpose of the present study was to:• Determine the pattern of antibiotic prescription among dentists of Kolkata.• Assess the attitude of dentists toward antibiotic resistance.An electronic version of the questionnaire of cross-sectional survey regarding antibiotic use and attitude toward growing antibiotic resistance was constructed using Qualtrics , an internet online survey tool that was e-mailed to dental surgeons of Kolkata registered with Indian Dental Association (IDA), West Bengal. A reminder e-mail was given after 1 month to recollect the responses from them.The survey was e-mailed to 300 dental surgeons, out of which 115 dental surgeons completed the survey, thereby achieving a response rate of 38.33%. Majority of the respondents (60%) chose amoxicillin in nonallergic patients. Average minimum duration of antibiotic therapy was 5 days. The drug of first choice for patients with an allergy to penicillin was erythromycin. The prime determinant of antibiotic use was facial swelling (68%). The prime determinant to select a particular brand of antibiotics was affordability of that brand (61%). Almost all (99%) dental surgeons were aware of antibiotic resistance being a growing concern. As per their views, there was overprescription of antibiotics.How to cite this article: Kaul R, Angrish P, Jain P, Saha S, Sengupta AV, Mukherjee S. A Survey on the Use of Antibiotics among the Dentists of Kolkata, West Bengal, India. Int J Clin Pediatr Dent 2018;11(2):122-127. This is the reason why antibiotics account for a huge majority of medicines being prescribed by dentists. It has been observed that contribution toward the problem of antibiotic resistance by dentists can be substantial as dentists prescribe 10% of all common antibiotics.2 Yingling et al3 concluded from findings of his study among members of the American Association of Endodontists (AAE) that they were prescribing antibiotics inappropriately. On the contrary, the National Center for Disease Control and Prevention found that almost one-third of all outpatient antibiotic prescriptions are unnecessary.4 We have now entered an era where some bacterial species are resistant to the full range of antibiotics presently available, with the methicillin-resistant Staphylococcus aureus and vancomycin-resistant Staphylococcus aureus being the most widely known example of extensive resistance.5 Keeping in mind the results obtained from previous studies, we took up the present study to investigate antibiotic prescribing practices of dentists. The aim of the present study was to determine the pattern of antibiotic prescription among dental surgeons of Kolkata and assess their attitude toward growing antibiotic resistance.Chemotherapy has been defined as the use of synthetic, semi-synthetic, and naturally occurring chemicals that inhibit specific organisms causing disease. The term “antibiotic” has been derived from combination of two words: Anti meaning “against” and biosis meaning “life.” Proper use of antibiotics along with surgical therapy is the most appropriate method to treat various odontogenic infections. Alexander Fleming, who along with Howard Florey and Ernst Chain shared the Nobel Prize in 1945 in Physiology and Medicine, addressed in his lecture: “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body.”The present study was designed as a descriptive cross-sectional study performed among the dentists of Kolkata registered under the IDA West Bengal Branch after obtaining ethical clearance from Ethics Committee, Dr. R Ahmed Dental College and Hospital, Kolkata, West Bengal, India. The study had a sample size of 300 dentists . InclusiPresent survey link was e-mailed to 300 dentists registered with IDA, West Bengal Branch, out of which 115 dentists completed the survey, thereby achieving a response rate of 38.33%. Responders of present survey included 62% males and 38% females with 71% respondents being <30 years of age; 51% respondents had run a practice of >5 years. Majority of the respondents were specialists, while a lesser number were general practitioners (23% BDS and 77% MDS). The main source of updated information regarding the use of antibiotics was found to be the latest editions of textbooks (57%). Most of the respondents (60%) chose amoxicillin in nonallergic patients [alone (37%) or associated with clavulanic acid (23%)]. Amoxi-cillin was prescribed as the first-choice antibiotic by 37% of respondents, which is appropriate for oral infection, while 34, 23, and 2% selected a combination of amoxicil-lin and metronidazole, amoxicillin/clavulanic acid, and ofloxacin + ornidazole respectively .If patient was found to be allergic to penicillin, drug of first choice in that case was erythromycin (53%), followed by azithromycin (22%) and clindamycin (19%). As per the results of the current study, the minimum duration of antibiotic therapy was 5 days for majority (59%), while a considerable number of respondents prescribed antibiotics for a minimum of 3 days (35%). Principal determinant for prescribing antibiotics was facial swelling (68%). Affordability of that particular brand (61%) was the factor that was primarily considered while prescribing a particular brand. Overall, evidence suggesting over prescription was found for the following conditions: reversible pulpitis (13%), irreversible pulpitis  with and4The decision to use an antimicrobial/antibiotic agent in managing an odontogenic infection is based on several factors. Clinician must first diagnose the cause of the infection and then determine the appropriate dental treatment that may include multiple modalities, including initiation of endodontic therapy and pulpectomy, mechanical or surgical disruption of that infectious environment. Before coming to a decision whether we require conjunctive antibiotic therapy, various factors, including host defense mechanisms, severity of the infection, magnitude of the extension of the infection, and expected pathogen, have to be taken into consideration. The fact that there is absence of collateral circulation within dental pulp makes the normal host defenses (inflammation and immunity) compromised, thereby making root canal system a unique environment to harbor a limited group of bacteria. The effectiveness of an oral antibiotic as first choice of treatment for an infection of odontogenic etiology is highly questionable as there is a lack of effective circulation in a necrotic pulp system. This concept reinforces the idea that surgery of some kind is the primary treatment of an infection of odontogenic source and that antibiotic therapy is simply an adjunctive care.3 and Spain.67 The overall response rate was 38.3%, and similar response rates were found in other published surveys.89The present study evaluated the antibiotic prescribing practices among the dental surgeons of Kolkata and their attitude toward growing concern of antibiotic resistance. In the present study, the questions were based on those in previous surveys developed in the USA10Endodontic infections typically have a rapid onset and short duration, most specifically if the cause is treated or eliminated. Prolonged courses of antibiotics destroy the commensal flora, thereby abolishing colonization resistance. The prescribing of systemic antibiotics hence needs to be justified. Broad spectrum of activity of amoxicillin, what is required for endodontic needs and its injudicious use in a healthy individual may contribute to the global antibiotic resistance problem.311 This study found that the second most frequently prescribed antibiotic for non-penicillin-allergic patients was a combination of amoxicil-lin and metronidazole (34%). On the contrary, as per the survey conducted in Spain, the leading antibiotic was amoxicillin plus clavulanic acid, followed by amoxicillin alone.12 Amoxicillin has also been found to be the most commonly prescribed antibiotic in European countries.13 In the present study, the drug of first choice in patients with an allergy to penicillins was found to be erythromycin (53%). In contrast to the results of the present study, clindamycin was the most prescribed drug in penicillin-allergic patients in the USA (21.6 and 57.03%)311 and Spain (63.2 and 65.4%).67 Other antibiotics prescribed for patients with an allergy to penicillins were azithromycin (22%) and clindamycin (19%).The results of the present study were in accordance to the results obtained from a study conducted in the USA and found that amoxicillin was prescribed only by 27.5% of members of the AAE.14 Clindamycin is a good choice if the patient is allergic to penicillin, although clindamycin has a low, but serious, risk of pseudomem-branous colitis.15Azithromycin does not find any role in oral infection because about 82% of oral streptococci develop resistance to macrolides after a single course.Metronidazole has been found to be very effective against obligate anaerobes, but not against facultative anaerobic bacteria. Hence, it becomes necessary for it to be used in conjunction with other agents. Moreover, if within 48 hours the patient is not responding to penicillin alone, one can consider adding metronidazole to the existing drug regimen.3 Treatment of most odontogenic infections requires an average of 5 to 7 days of therapy; however, treatment of severe infections or immunocompromised patients’ therapy can be of longer duration owing to reduced immunity. A rule of thumb when prescribing is that the antibiotic should last for 3 days after the patient’s symptoms have been resolved.3Inadequate duration of the therapy or overdosing of the antibiotics has resulted in damaging the host response, thereby producing toxic effects.In the present study, many respondents (35%) responded that they will give antibiotics for a minimum of 3 days. Patient compliance also plays a major role in effective treatment. Most of the patients stop the drug therapy as and when initial symptoms are resolved. Affordability of brand was considered main factor while prescribing a particular brand. The drug may be too expensive or not covered by a third-party payer and the prescription remains unfilled. An alternative to this can be prescribing generic drugs.Dosing frequency may be complicated. The compliance issue most often observed is missed doses after clinical symptoms have subsided. Another challenge to compliance is the untoward or unexpected side effects that can occur when taking antibiotics. In all these cases, there is a chance for mutated microbes to flourish and thereby causing serious consequences.318Endodontic conditions like reversible pulpitis, irreversible pulpitis with moderate/severe preoperative symptoms, with or without acute periodontitis do not warrant antibiotic coverage. Despite these facts, we found in our present study that 35% respondents prescribed antibiotics prior to beginning of treatment. This finding is slightly higher than those reported in previous studies.6 and American dentists.3 Rational use of antibiotics is based on well-defined indications in cases of infection of endodontic origin.Necrotic pulp with dentoalveolar abscess, with or without fistula, with no swelling, and no/mild symptoms does not require use of antibiotics as treatment can be restricted to nonsurgical root canal therapy; however, 56% respondents of this study population reported antibiotic use. In the present study, a higher percentage of dentists prescribed antibiotics for necrotic pulp with chronic apical periodontitis with sinus tract and no/mild preoperative symptoms as compared with that prescribed by Spanish1920 This outcome suggests that the scientific basis for prescribing antibiotics was ignored by the majority of the dental surgeons. Dental surgeons need to have a thorough understanding of the clinical indications for antibiotic prescription in order to prevent the misuse or overuse of these drugs.20 Since the majority of respondents were young, i.e., age <30 years, it is their duty toward society to initiative not to repeat these practices, instead help in prevention of resistance problem which is now accepted as a challenge worldwide.Therefore, antibiotics must be considered only as an adjunct to conventional root canal therapy or when emergency treatment is not possible.We need to consider the results of this study in light of some study limitations. Since the survey was self-administered, responses may have been subject to response bias. The dentists who participated may not be the representative of dentists of Kolkata. Although a few trends were evident, the sample size was small and thus inferences were difficult.Despite all these limitations, this study has several strengths, including being the first in the region to our knowledge to report on this topic of importance and clinical relevance. The study results provide preliminary data regarding extent to which professionals were adhering to professional guidelines. The data also included patterns among not only general dentists but also all specialties. The present study sets the stage for further research.Dental surgeons in Kolkata were found to overprescribe antibiotics, which could be a major contributor to the worldwide problem of antimicrobial resistance. Most of the respondents of this survey were young dentists. It is their responsibility to curb this problem instead of going along with the flow. There is an urgent need to raise public and professional awareness regarding the risks of injudicious use of antibiotics in dentistry.


Pluronic F127 exhibits thermogelling behaviour at 20–30 °C via a micelle packing mechanism. Disruption of the micelle packing increases the sol-gel temperature, but results in the decrease of modulus. Herein, we reported a method to modify F127 with polyhedral oligosilsesquioxane (POSS) to impart a higher gelling temperature without yielding the property and strength of the thermogel. The thermal degradation temperature was enhanced to 15 °C after POSS incorporation and the gelling temperature shifted 10 °C higher, without sacrificing the modulus of the gel. Rheological studies supported the claim that the gel property was reinforced after POSS incorporation. F127-POSS copolymer matrix stored more energy from POSS reinforcement, which saw larger Lissajous curve areas before the collapse of the microstructure for the same amount of stress applied. These results indicated that modification with POSS would raise the sol-gel transition temperature without sacrificing the modulus of the gel. Pluronic F127 is an amphiphilic block copolymer of PEG-PPG-PEG structure (PEG: poly(ethylene glycol); PPG: poly(propylene glycol)). The central PPG block becomes hydrophobic, while the PEG blocks remain hydrophilic and above a critical temperature, self-aggregating into micelles. At high enough concentration, these aggregated micelles form a gel. The use of Pluronic F127 could be vastly applied in pharmaceuticals, protein/drug delivery, and tissue engineering . These sco-glycolic acid)-block-poly(ethylene glycol)) methacrylate (poly((PLGA-b-PEG)MA)) copolymer aqueous solution sol-gel transition behavior with increasing temperature [g-chitosan due to changes in the balance between hydrophilicity and hydrophobicity [g-chitosan sol-gel transition driven by hydrophobic interactions, the mPEG-g-chitosan chains formed aggregates, resulting in the formation of a gel network. A study by Kadla and Korehei explained the effect of hydrophilic and hydrophobic interactions on rheological behaviour and gel microstructure [Several studies reported the effect of hydrophilic/hydrophobic interactions on sol-gel transition and moduli properties. Aqueous Pluronic solutions are known to undergo sol-to-gel transition through a shift from unimer to micelle. High hydrophilic content minimized hydrophobic interactions which reduced the micelle aggregation tendency. The transformation from sol to gel would be difficult, resulting in the increase in the sol-to-gel transition temperature . Kim et perature . As the hobicity . Elevatetructure . Increas4-b-PEG10K-b-P(MA-POSS)4 were able to form a gel in water at ~8.8 wt %, while diblock copolymers cannot. Subsequently, they tailored gelation of (PEG−P(MA-POSS)) block copolymers by adding hydrophobic POSS  nanoparticles [b-P(MA-POSS) and PDLA-b-P(MA-POSS)). Increasing the length of the (MA-POSS) block in the copolymer resulted in a size decrease of hybrid nanoparticles [Studies have reported on the incorporation of polyhedral oligosilsesquioxane (POSS) as physical and chemical modifiers in polymeric systems . POSS isarticles . Vinyl garticles . They fuarticles . They alarticles . The groarticles .w/w) [Tg) after incorporation of POSS. Wunder et al. synthesized a POSS-PEG copolymer blended LiClO4 and methyl cellulose to enhance the property of the solid polymer electrolytes [Tg) of blends indicated the reinforcement of conductive POSS-PEG to the LiClO4 partitions.This nanocaged framework makes POSS thermally and chemically robust and, thus, rendered it suitable as a viscosity modifier , mechaniw/w) . They obtrolytes . The incTg) of the polymer nanocomposite [Herein, we reported F127 modification by incorporation of methacryloisobutyl-POSS (MA-POSS) to enhance mechanical and thermal properties. Studies on MA-POSS-based polymers have shown effective improvement in the glass transition temperature , 1,1,4,7,10,10-hexamethyltriethylenetetramine , copper (I) bromide (CuBr) (99%), triethylamine, 2-bromoisobutyryl bromide, tetrahydrofuran (THF) anhydrous, and ethyl ether anhydrous were obtained from Aldrich, Singapore. Methacrylisobutyl POSS (MA-POSS) was purchased from Hybrid Plastics, Hattiesburg, US (product #: MA0702). All chemicals were used as received without further purification. Purified nitrogen was used in all of the reactions.v/v). The crude product was purified by dissolving in tetrahydrofuran (THF) and any residual reactants were removed by precipitation twice with hexane and dried in vacuum for subsequent ATRP. F127-poly(methacrylisobutyl POSS) (F127-p-MA-POSS) copolymers were synthesized using two different molar feed ratios of F127:MA-POSS, 1:4 and 1:8, respectively. As mentioned, hydrophilic property of F127 would be altered by the addition of hydrophobic MA-POSS. Therefore, to ensure minimal solubility of polymer in water the maximum ratio of POSS to be added to F127 was investigated to be 1:8 (F127:MA-POSS). The feed amount used for each synthesis is listed in F127 initiator for ATRP was synthesized according to previous report . F127 (11H NMR (400 MHz) was used to determine the structures of polymers synthesized. The spectra were recorded with a Bruker AV-400 NMR spectrometer  in chloroform-d (CHCl3) at room temperature. A 30° pulse width, 5208 Hz spectral width, and 32,000 data points were used for the measurement. The acquisition time was set to 3.2 s with a pulse repetition time of 2.0 s. Chemical shift was normalized to the solvent peaks (δ = 7.26 ppm for CHCl3). Molecular weight was measured with gel permeation chromatography  with a Shimadzu SCL-10A and LC-8A system, equipped with a Shimadzu RID-10A refractive index detector  and two 5 μm Phenogel 50 and 1000 Å columns (size: 300 × 4.6 mm) in series. In both measurements, THF was used as eluent at 40 °C, and flow rate of 0.30 mL·min−1. The calibration curve was performed with monodisperse polystyrene standards.Characterizations of the polymers were carried out as previously reported ,25. 1H N−1 under dynamic nitrogen flow at 70 mL·min−1.Thermogravimetric analysis (TGA) was performed on a TA Instruments SDT 2960 . Samples were heated from 30–800 °C with heating rate of 20 °C·min−1, at constant strain of 1.25%, and angular frequency of 10 rad·s−1. Dynamic oscillatory amplitude tests were performed by varying the strain from 0.5%–150% at 25 and 30 °C, respectively, at constant frequency of 1 Hz. Lissajous curves were recorded with a sampling time of 3 s. A solvent-trap cover (TA Instruments) was applied during each test to prevent water evaporation.Rheological tests were performed with a Discovery Hybrid Rheometer  fitted with a 20 mm parallel plate geometry. Temperature was regulated by a Peltier plate system used to report temperature-responsive behaviour of the polymer. Temperature sweep tests were performed with an oscillation temperature ramp of 25–45 °C at a ramp rate of 1 °C·s1H NMR spectra 2–O–) together with (–O–CH2–) in the F127 backbone. –CH3 groups of MA-POSS could be found around 1.13 ppm. A slight variation in signals could be related to the amount of MA-POSS present in the sample. A slight downward shift in signal could be observed as the degree of MA-POSS increased in the sample. Resonance peaks observed at δ ~0.94–0.96 and 0.609 ppm could be assigned to –CH3 and –CH2– groups of isobutyl of MA-POSS, respectively [The polymer was synthesized as shown in ectively ,27. With−1 in nitrogen atmosphere  to that of F127 . In LAOS, the G’ and G” moduli became a function of the strain amplitude at a fixed frequency and the resulting stress waveforms were distorted from sinusoidal waves, defined as the non-LVE region [Oscillatory amplitude sweeps were performed on 15 wt % aqueous solutions of F127 and F127-POSS at two different temperatures (25 and 30 °C) to study the effect of POSS incorporation under linear viscoelastic region (LVE) ,39,40. FE region ,42. Thisy-axis) vs. strain/strain rate (x-axis), used to predict the generic behavioural mechanism of deformation [The oscillatory stress sweeps data could extract additional information represented by Lissajous curves to further analyse the microstructure of polymer. Lissajous curves , and the end point. The different Lissajous shapes indicated a microstructural change of the samples during the oscillatory amplitude sweep. The area enclosed by the Lissajous curve corresponded to the energy dissipated per unit volume sample in a single LAOS cycle [Three points were selected for Lissajous curves as shown in OS cycle . At low In this work, MA-POSS was used to modify the thermal and mechanical properties of F127 with the addition of trace amounts of POSS. MA-POSS was successfully incorporated in F127 via atomic transfer radical polymerization (ATRP). Thermogravimetric analysis depicted the onset of thermal decomposition temperature of F127-POSS was enhanced 15 °C compared to F127. The weight loss of 5% and 10% temperature was increased 34.0 and 28.3 °C respectively after POSS incorporation. Subsequently, rheological studies were performed to investigate the gel property affected by POSS incorporation. Thermal gelation of F127-POSS composite solution shifted 10 °C higher, from 23.5 to 33.5 °C, than F127 precursor, while the modulus of the gel was well maintained. A stress-strain Lissajous curve extracted from oscillatory amplitude test was used to investigate the change in the gel microstructure subjected to oscillatory strain. The area enclosed by the Lissajous curve changing with strain revealed the energy dissipated per unit volume sample, to further reflect the strength change of the gels and the molecular interaction in the gel with strain. In summary, trace amounts of MA-POSS incorporation in F127 reserved the intrinsic thermal responsive gelation property of F127 and was able to shift the gelation temperature 10 °C higher, while the strength of the hydrogel was not sacrificed. Moreover, the thermal degradation temperature was successfully extended up to 34.0 °C. It was also reported that POSS incorporation induced a polymer antibacterial property , which w


Supplemental Digital Content is Available in the Text. Evidence-based HIV interventions often fail to reach anticipated impact due to insufficient utilization in real-world health systems. Human-centered design (HCD) represents a novel approach in tailoring innovations to fit end-users, narrowing the gap between efficacious interventions and impact at scale.We combined a narrative literature review of HCD in HIV programs with our experience using HCD to redesign an intervention promoting patient-centered care (PCC) practices among health care workers (HCW) in Zambia. We summarize the use and results of HCD in the global HIV response and share case study insights to advance conceptualization of HCD applications.The literature review identified 13 articles (representing 7 studies) on the use of HCD in HIV. All studies featured HCD hallmarks including empathy development, user-driven inquiry, ideation, and iterative refinement. HCD was applied to mHealth design, a management intervention and pre-exposure prophylaxis delivery. Our HCD application addressed a behavioral service delivery target: changing HCW patient-centered beliefs, attitudes, and practices. Through in-depth developer–user interaction, our HCD approach revealed specific HCW support for and resistance to PCC, suggesting intervention revisions to improve feasibility and acceptability and PCC considerations that could inform implementation in transferable settings.As both a research and implementation tool, HCD has potential to improve effective implementation of the HIV response, particularly for product development; new intervention introduction; and complex system interventions. Further research on HCD application strengths and limitations is needed. Those promoting PCC may improve implementation success by seeking out resonance and anticipating the challenges our HCD process identified. Although an emergency-based response focusing on access largely drove HIV service delivery strategies over the past three decades, future success depends on more effectively engaging end-users with appropriate, desirable, and accessible services.2 For example, although ART is lifesaving, both treatment initiation and retention remain suboptimal, leading to onward transmission, morbidities, and mortality.3 These gaps demand alternative and innovative treatment delivery models—drawing from interdisciplinary perspectives—for advancing the public health response.5Although today's public health response to HIV has a robust set of evidence-based tools with which to address the global epidemic , implementation has failed to achieve the tools' full preventive and therapeutic potential.8 Traditionally, HCD focused on product development using participatory activities emphasizing researcher and user interaction to improve intervention utility, uptake, sustainability, and effectiveness.9 Although no single definition of HCD in health exists,6 there are hallmarks present across HCD applications9 .Human-centered design (HCD) is an emerging approach with roots in industrial design, engineering, psychology, anthropology, business, computer science, ergonomics, and design that hold promise for improving implementation of evidence-based interventions for health. HCD brings end-users and developers together to cocreate health products, services, or delivery strategies that identify, prioritize, and address barriers to usability.s9 Table . HCD use6 no synthetic appraisal of HCD in the public health HIV response yet exists. In this article, we seek to advance the conceptualization of the use of HCD to address HIV through both a literature review and a case study of our own experience using HCD methods to advance patient-centered care (PCC) in HIV treatment in Zambia.17 The literature review summarizes the following: (1) outcomes to which HCD has been applied, (2) methods used, (3) results and effectiveness, and (4) lessons learned. We present HCD-derived case study insights that could be informative to others seeking to optimize the delivery of PCC HIV interventions in transferable contexts. In addition, we hope this article will call attention to opportunities to advance HCD as a tool for adapting implementation strategies to particular contexts and end-user populations to strengthen the public health response to HIV.Despite a growing literature on HCD in health,19 of published articles and the grey literature on HCD in the global HIV response. Article inclusion criteria are as follows: (1) published through the search date of May 22, 2019, (2) related to HIV, and (3) presented data on HCD. Articles were excluded if they did not describe a design process or if they explicitly attributed their methods to non-HCD methodology . To identify the grey literature, we conducted targeted searches of websites from 3 HCD design leaders6 and another organization using HCD for health known to the authors, including any HIV-related cases on the website as of the search date. Case studies not articulating HCD methods or results were excluded. LB screened identified titles, abstracts, and case summaries using the inclusion criteria. LB and AB reviewed relevant full-text articles, abstracting the study author, participants and setting, HCD methods described, results, strengths, limitations, and lessons learned.We conducted a narrative literature review22 and a desire for differentiated care delivery options23 as drivers of poor retention, with high health facility-level variability.24 In response, the PCPH study's intervention was conceived to comprise (1) training of health care workers (HCW) in the principles and practices of patient-centeredness; (2) collecting and sharing data with HCW on the patient experience at the health facility; (3) HCW coaching; (4) supporting facility-level quality improvement; and (5) incentives for improved practice.We supplement the literature review with our experience applying HCD to shape a PCC intervention. The “Person Centred Public Health for HIV Treatment in Zambia Study” (PCPH) is a stepped wedge, cluster-randomized trial of a PCC intervention to improve HIV patient retention in care in Lusaka, Zambia, starting in mid-2019 implemented by the Centre for Infectious Disease Research in Zambia (CIDRZ), a partner to the Ministry of Health in HIV service provision since 2003. Our previous research in Zambia identified poor patient–provider interactions9 (HMW) to guide the workshop:Coaching: How might coaches be best positioned in health facilities to guide and support HCWs in delivering PCC according to best practices and in ways that are appropriate to facility context?;HCW support and motivation: How might we foster a workplace culture that empowers and motivates health care providers to provide PCC?;Information management: How might we make new and existing information on patient experience and patient outcomes accessible, desirable, and useable for facility staff and other key users?Before trial implementation, we undertook a pilot study implementing elements 1–3 of the planned intervention in 2 facilities to understand the context and test and refine the intervention. We conducted formative research on intervention components using interviews and focus-group discussions (FGDs). We then held a 5-day HCD workshop to engage HCWs who experienced the pilot in co-design activities to further refine the study intervention. Key HCD workshop strategies included the following: (1) developers cultivating empathy with HCWs and learning from insights and experiences, (2) developers and HCWs collaborating in investigation and creative problem-solving, and (3) defining actionable approaches for intervention improvement. Drawing on previous research and pilot findings, we defined 3 “How Might We…?” questions25 invited HCWs (users) from the pilot facilities , 6 district health management team representatives (influencers) and 12 research team members (developers). The workshop agenda  included common HCD insight gathering activities such as “journey maps”9 and personas26 to realize the workshop strategies. Workshop facilitation was led by an external HCD expert and co-facilitated by research team members.The design workshop included 31 purposefullyhttp://links.lww.com/QAI/B389). The developers took notes during each workshop session and, each day, reviewed outputs and notes, and dialogued to identify key questions, emergent insights, and direct feedback on intervention components. Developers then categorized the insights through mapping and rapid thematic analysis8 and proposed intervention revisions. Critical insights and themes were discussed with HCWs.To synthesize insights, participants generated visualized activity outputs common to HCD  outcome implementation not informed by users or (2) informed by another formative research approach , the basic form of which was justified by previous research. Two studies,38 both focused on a newer product and a less well-understood user group (PrEP for young women), sought more broadly to understand experiences and approaches relevant to increasing and sustaining PrEP use and then proceeded to design and refine specific PrEP products and processes. Articles reflect that even when specific products are of interest, HCD processes require sufficient flexibility during the user-driven investigation stages to allow for user priorities to guide the focus and form of the final solutions designed. For example, although based on an electronic medical record system, the final HIV-TB integration support tool design utilized paper-based messaging to clinicians as the most feasible form of communication.28In each study, the HCD application was guided by the current state of research and the user behaviors desired by the developers. Most of the studies sought to create and optimize a specific outcome  resonated with HCW but met resistance with some HCWs such as time constraints and beliefs that punitive measures improve patient compliance. During HCD activity dialogues, HCW participants shared stories of using kindness to help struggling patients to re-engage in care, highlighting the ability to implement PCC under less-than-ideal conditions and the benefits of positive interactions. The explicit encouragement of HCD to offer multiple perspectives and dialogues and embrace a co-creative environment allowed for the interactions, which revealed these various perspectives. The key points of resonance with PCC Table  and resiIntervention components that will be tested in our stepped-wedge trial were revised to improve acceptability, appropriateness, and feasibility of PCC practices, including better-using intervention mentoring and data collection to help HCWs feel visible, appreciated, and accountable. For example, HCD insights led us to augment the planned HCW FGD data collection with a quantitative HCW survey to expand and anonymize HCW feedback (additional examples in Table Our review suggested that HCD offers an important and emerging tool for adapting strategies to enhance ART services. While traditionally applied to products or mHealth practices, we and others have also begun to apply these principles to shape and refine the service delivery context and patient experience. Overall, HCD has the potential to improve the HIV response by more closely aligning the implementation of evidence-based products and processes with user priorities and context. In an HIV response that has to date rightly prioritized scale-up and standardization, but which now must shift to a more targeted efforts to continue improvements, HCD offers a theoretically based, robustly mapped set of practices that seek to improve outcomes through active engagement and respect for end-user views; encouragement of broad, creative inquiry; and support for iterative idea refinement in response to testing and feedback. Rigorous, successful HCD outcomes are no panacea however, and likely depend on relationships, time, and other resources required for authentic engagement and responsiveness, which may not always be available.40 The HCD approach in EMOTION37 identified that the medical appearance of PrEP was associated with illness, creating a likely barrier to young women's uptake and use. EMOTION29 thus prototyped PrEP starter kits that resemble make-up bags and stickers to disguise standard labels. User engagement lessons may facilitate use in similar populations.Extant evidence lacks an assessment of the comparative effectiveness of HCD and non-HCD processes in implementation optimization. Recent research, however, offers interesting insight into potential HCD gains. A study of the national scale-up of PrEP in Kenya identified that in addition to other stigma types, product stigma, including the similar appearance of PrEP bottles and ARV bottles, was a barrier to PrEP use.41 There is often overlap in objectives and methods between HCD, more traditional qualitative methodologies43; participatory research11; engineering approaches45; and discrete choice experiments as formative research.46 Although efforts have been made to compare and contrast approaches,8 distinctions are not concrete. Authors struggled to adjudicate use of HCD in some studies in our literature review. The Schnall et al34 study discussed a user-centered design process but grounded their research in the Information System Research Framework and described some of their methods as participatory action research. We erred on the side of inclusion, but the multidisciplinary nature of user-centered approaches requires reviewers' interpretation of methods. HCD distinguishes itself in by focus on empathy; flexibility in inquiry as directed by users; iterative, rapid testing cycles; and emphasis on practical outcomes. Our own case study included both traditional formative research and HCD. Although our more traditional formative research raised the issue of HCW context and the need to avoid blame to increase receptivity of HCWs to PCC, the empathy established and nuance understood through the HCD workshop elevated the HCW experience to formally include improvement in the HCW experience in the study Theory of Change.HCD approaches are not the only user-engagement methods that may support improved implementation. A 2017 landscape mapping of end-user research in HIV prevention for young women in sub-Saharan Africa identified 53 projects, of which 3 were explicitly HCD.47 a metric of qualitative rigor that considers the applicability of findings from one setting to a different setting with a similar context, instead of generalizable. Potential for transferability was noted in several literature review studies,29 as well as our own HCD case study. Critical reflection on HCD limitations would enhance future use. For example, thin preliminary knowledge of the evidence-based intervention may lead to poor design questions. An HCD process that is too rapid to allow for sufficient iteration or diversity of user engagement may produce results that lack rigor. Based on the importance of open discussion in our workshop, we believe that an absence of mutual respect and trust between users and developers could prevent empathetic interactions and produce inauthentic HCD outcomes.The limitations of HCD identified in the literature review including a lack of generalizability and inability to estimate effectiveness are not dissimilar to other qualitative methodologies. Instead of limitations, they are features of the approach. HCD findings may be transferable,28 our team felt that the communication, collaboration, and engagement between planners and users during HCD can support successful intervention implementation subsequent to the design phase.An important HCD insight from our workshop was that effective implementation of an intervention to increase the patient-centeredness of care through HCW behavior change needs to be implemented in a provider-centered way. This does not diminish the central role of patients in their care processes and outcomes. It highlights that just as the lived realities of the patients' need to inform HCW engagement with patients as care partners, the lived realities of the HCWs demand that interventions to change HCW practice prioritize feasible, acceptable, and appropriate implementation strategies. HCD may be particularly appropriate in complex settings that need to consider patient, provider, and systems realities. The compendium of resonance and resistance to PCC Tables  and 5 prOur review may have missed relevant case studies given the limited grey literature search and the practical outputs of many HCD studies, which are less likely to be published in peer-reviewed manuscripts. Similarly, we focused on HIV-related HCD, excluding possible lessons from other health areas. Owing to time and resource constraints, our HCD process did not include patients, the intended intervention beneficiaries, and key actors in their own care and treatment. Inclusion of patients would almost certainly have identified additional insights and intervention revisions. Our choice to focus on the HCWs allowed us to engage with the primary users of the planned intervention, to conduct our HCD approach in limited time, and to manage identified power dynamics within HCW cadres based on shared knowledge and vocabulary from the pilot phase.49 approach to bridge this gap; more studies that document and critically reflect on the use and impact of HCD methods in the global HIV response are needed to guide their effective use. Those seeking to promote PCC may improve implementation success by seeking out the resonance and anticipating and defusing the challenges our HCD process identified.HCD has the potential to improve effective implementation of the HIV response by tailoring implementation strategies to enhance evidence-based interventions in particular service delivery settings. Although HCD is a promising and increasingly advocated