Enzymatic and Non-enzymatic Collagen Cross-Links and Fracture Occurrence in Type 1 Diabetes Patients.

Increased fracture risk in type 1 diabetes (T1D) patients is not fully captured by bone mineral density (BMD) by DXA. Advanced glycation end-products (AGEs) have been implicated in the increased fracture risk in T1D, yet recent publications question this. To test the hypothesis that enzymatic collagen cross-links rather than AGEs correlate with fracture incidence in T1D, we analyzed iliac crest biopsies from sex-matched, fracturing T1D patients (N = 5; T1DFx), 6 non-fracturing T1D patients (T1DNoFx), and 6 healthy subjects, by Raman microspectroscopy as a function of tissue age (based on double fluorescent labels), in intracortical and trabecular bone, to determine pyridinoline (Pyd), ε-N-Carboxymethyl-L-lysine, and pentosidine (PEN)). There were no differences in the clinical characteristics between the T1DFx and T1DNoFx groups. At trabecular forming surfaces, T1DFx patients had higher PEN and Pyd content compared to T1DNoFx ones. Previous studies have shown that elevated PEN does not necessarily correlate with fracture incidence in postmenopausal, long-term T1D patients. On the other hand, the elevated Pyd content in the T1DFx patients would be consistent with published studies showing a significant correlation between elevated trivalent enzymatic collagen cross-links and fracture occurrence independent of BMD. Collagen fibers with high Pyd content are more brittle. Thus, a plausible suggestion is that it is the enzymatic collagen cross-links that either by themselves or in combination with the adverse effects of increased AGE accumulation that result in fragility fracture in T1D.

Same day discharge following non-elective PCI for non-ST elevation acute coronary syndromes.

BACKGROUND AND AIM: Timing of discharge after percutaneous coronary intervention (PCI) is a crucial aspect of procedural safety and patient turnover. We examined predictors and outcomes of same-day discharge (SDD) after non-elective PCI for non-ST elevation acute coronary syndromes (NSTE-ACS) in comparison with next-day discharge (NDD). METHODS: Baseline demographic, clinical, and procedural data were collected as were in-hospital outcomes and post-PCI length of stay (LOS) for all patients undergoing non-elective PCI for NSTE-ACS between 2011 and 2014 at a central tertiary care center. Thirty day and 1-year mortality and bleeding as well as 30-day readmission rates were determined from social security record and medical chart review. Logistic regression was performed to identify predictors of SDD, and propensity-matched analysis was done to examine the differences in outcomes between NDD and SDD. RESULTS: Out of 2,529 patients who underwent non-elective PCI for NSTE-ACS from 2011 to 2014, 1,385 met the inclusion criteria (mean age = 63 years; 26% women) and were discharged either the same day of (N = 300) or the day after (N = 1,085) PCI. Thirty-day and one-year mortality and major bleeding rates were similar between the 2 groups. Logistic regression identified male sex, radial access, negative troponin biomarker status, and procedure start time as predictors of SDD. In propensity-matched analyses, there was no difference in 30-day mortality and readmission between SDD and NDD groups. CONCLUSIONS: SDD after non-elective PCI for NSTE-ACS may be a reasonable alternative to NDD for selected low-risk patients with comparable mortality, bleeding, and readmission rates.

Bone-targeting liposome formulation of Salvianic acid A accelerates the healing of delayed fracture Union in Mice.

Delayed fracture union is a significant clinical challenge in orthopedic practice. There are few non-surgical therapeutic options for this pathology. To address this challenge, we have developed a bone-targeting liposome (BTL) formulation of salvianic acid A (SAA), a potent bone anabolic agent, for improved treatment of delayed fracture union. Using pyrophosphorylated cholesterol as the targeting ligand, the liposome formulation (SAA-BTL) has demonstrated strong affinity to hydroxyapatite in vitro, and to bones in vivo. Locally administered SAA-BTL was found to significantly improve fracture callus formation and micro-architecture with accelerated mineralization rate in callus when compared to the dose equivalent SAA, non-targeting SAA liposome (SAA-NTL) or no treatment on a prednisone-induced delayed fracture union mouse model. Biomechanical analyses further validated the potent therapeutic efficacy of SAA-BTL. These results support SAA-BTL formulation, as a promising therapeutic candidate, to be further developed into an effective and safe clinical treatment for delayed bone fracture union.

Effect of Macroanatomic Bone Type and Estrogen Loss on Osteocyte Lacunar Properties in Healthy Adult Women.

This is the first study to examine clinical human bone specimens by three-dimensional imaging to characterize osteocyte lacunar properties as a function of macroanatomic bone type and estrogen loss. We applied laboratory-based instrumentation [3D X-ray microscope (3DXRM), MicroXCT-200; Carl Zeiss/Xradia, Inc.] that reaches the same resolution as synchrotron microscopy. We used serial transiliac bone biopsy specimens to examine the effect of macroanatomic bone type and estrogen status on osteocyte lacunar properties. These properties include lacunar size (volume, axes lengths of the ellipsoidal lacunar voids), distribution (density, average near-neighbor lacunar distance), and shape factors (sphericity ratio, average eigenvalues, degree of equancy, elongation, and flatness) in both cortical and trabecular bone tissue. The lacunar properties (volume, surface area, density, near-neighbor distance, etc.) and the shape factors (E1, L1, L2, degree of equancy, degree of elongation) were different between cortical and trabecular bone regardless of estrogen status. In cortical bone and trabecular nodes, the lacunar void volume and surface area were either smaller or tended to be smaller in postmenopausal as compared to premenopausal women. The void volume-to-bone volume ratio of cortical bone showed declining trends with estrogen loss. While there were differences between trabecular and cortical bone tissue, the lacunar void sphericity ratio for trabecular struts shows decreasing trends in postmenopausal women. These data suggest that using 3DXRM can provide new insight into osteocyte lacunar properties in transiliac bone biopsies from patients with various skeletal disease/conditions and pharmaceutical treatments.

Risk-adapted stratification for optimally intensive treatment assignment of pediatric patients with non-Hodgkin lymphoma is an effective strategy in developing countries.

BACKGROUND: Pediatric patients with non-Hodgkin lymphoma (NHL) in developing countries (DCs) present with greater tumor load even at lower stages and with comorbidities that impact therapy delivery. This causes toxic mortality with "standard" intensive protocols or recurrences with "gentler" treatment. OBJECTIVES: We developed and evaluated a risk stratification schema that guides intensity of therapy. DESIGN/METHODS: Sixty-nine patients were prospectively assigned to five risk groups (A-E; n = 6, 15, 16, 15, and 17) following staging and treated with protocols of risk-stratified intensity. Risk stratification utilized St. Jude stage, disease bulk, and sites involved. RESULTS: Between 2006 and 2011, 69 patients with B-cell NHL were enrolled. Among these, 72.5% were boys with mean age of 6.9 years (±3.33 [SD]; range 2.4-14.2 years). Eighty-seven percent had Burkitt lymphoma, 82.6% had advanced stage (25 [36.2%] stage III; 32 [46.4%] stage IV), and 24.6% were central nervous system positive. Mean lactate dehydrogenase increased progressively across the risk strata. Among these, 0/6, 1/15, 3/16, 2/15, and 7/17 patients relapsed/progressed within each risk stratum. Fifteen patients died; three from treatment-related toxicity. At a median follow-up of 6.2 years, the overall and event-free survival (EFS) for all patients was 78.1 and 75.4%, respectively; EFS was related to risk assignment. The frequency of documented infectious and noninfectious toxicities increased with higher risk group assignment causing prolongation of admissions and potential treatment delays. CONCLUSIONS: Reduction in treatment intensity for an identified subset of patients with NHL is feasible, while high-intensity therapy is required for high-risk groups. This risk stratification system may be a first step toward improving the outcomes in some DCs.

Dexamethasone prodrug treatment prevents nephritis in lupus-prone (NZB × NZW)F1 mice without causing systemic side effects.

OBJECTIVE: To evaluate the potentially improved therapeutic efficacy and safety of nephrotropic macromolecular prodrugs of glucocorticoids (GCs) for the treatment of lupus nephritis. METHODS: Lupus-prone female (NZB × NZW)F1 mice received monthly injections of N-(2-hydroxypropyl) methacrylamide copolymer-based dexamethasone prodrug (P-Dex) or daily injections of dexamethasone phosphate sodium (Dex; overall dose equivalent to that of P-Dex) for 2 months. During treatment, the mice were monitored for albuminuria, mean arterial pressure, and serum autoantibody levels. Nephritis, renal immune complex levels, and macrophage infiltration were evaluated histologically. Bone quality was analyzed using peripheral dual x-ray absorptiometry and micro-computed tomography. The in vivo distribution of P-Dex was investigated using optical imaging, immunohistochemistry, and fluorescence-activated cell sorting (FACS). The antiinflammatory effect of P-Dex was validated using lipopolysaccharide-activated human proximal tubule epithelial (HK-2) cells. RESULTS: Monthly P-Dex injections completely abolished albuminuria in the (NZB × NZW)F1 mice; this approach was significantly more efficacious than daily Dex treatment. P-Dex treatment did not reduce serum levels of anti-double-stranded DNA antibodies or renal immune complexes but did decrease macrophage infiltration, which is a marker of chronic inflammation. Immunohistochemical and FACS analyses revealed that P-Dex was primarily sequestered by proximal tubule epithelial cells, and that it could attenuate the inflammatory response in HK-2 cell culture. In contrast to Dex treatment, P-Dex treatment did not lead to any significant deterioration of bone quality or reduction in the level of total serum IgG. CONCLUSION: Macromolecularization of GCs renders them nephrotropic. Protracted retention, subcellular processing, and activation of GC prodrugs by kidney cells would potentiate nephritis resolution, with a reduced risk of systemic toxicities.

Frequency of beta-thalassemia trait in families of thalassemia major patients, Lahore.

BACKGROUND: Thalassemia major is one of the most common genetic disorders in Pakistan and over five thousand new patients are added in the pool annually. This familial disease has both medical and social implications, and therefore there is a need to assess the magnitude of beta-Thalassemia trait amongst family members of Thalassemia major patients. METHODS: This cross-sectional descriptive study enrolled 674 blood samples from first degree relatives of registered patients of Thalassemia major at Sir Ganga Ram Hospital, Lahore. Peripheral blood smears were studied for abnormal morphology findings of microcytosis, hypochromia, poikilocytosis (tear drops, target cells) and Erythrocyte indices (haemoglobin, RBCs, mean corpuscular haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin concentration) and Hb electrophoretic (HbA, HbA2, & HbF). RESULTS: Hb electrophoresis showed 61% of the study subjects had haemoglobinopathies. Frequency of beta-Thalassemia trait was highest followed by beta-Thalassemia major, HbE trait, HbD Punjab and Hb intermedia. CONCLUSION: Findings strongly suggest screening for beta-Thalassemia trait in families of Thalassemia major patients.

Cellulose Degradation Enzymes in Filamentous Fungi, A Bioprocessing Approach Towards Biorefinery.

The economic exploration of renewable energy resources has hot fundamentals among the countries besides dwindling energy resources and increasing public pressure. Cellulose accumulation is a major bio-natural resource from agricultural waste. Cellulases are the most potential enzymes that systematically degrade cellulosic biomass into monomers which could be further processed into several efficient value-added products via chemical and biological reactions including useful biomaterial for human benefits. This could lower the environmental risks problems followed by an energy crisis. Cellulases are mainly synthesized by special fungal genotypes. The strain Trichoderma orientalis could highly express cellulases and was regarded as an ideal strain for further research, as the genetic tools have found compatibility for cellulose breakdown by producing effective cellulose-degrading enzymes. This strain has found a cellulase production of about 35 g/L that needs further studies for advancement. The enzyme activity of strain Trichoderma orientalis needed to be further improved from a molecular level which is one of the important methods. Considering synthetic biological approaches to unveil the genetic tools will boost the knowledge about commercial cellulases bioproduction. Several genetic transformation methods were significantly cited in this study. The transformation approaches that are currently researchers are exploring is transcription regulatory factors that are deeply explained in this study, that are considered essential regulators of gene expression.

High-Output Heart Failure in a Patient With Klippel-Trénaunay Syndrome: A Case Report.

Klippel-Trénaunay syndrome (KTS) is a rare and complex congenital syndrome defined as the triad of cutaneous capillary malformation, bone and soft tissue hypertrophy, and venous and lymphatic malformations. KTS is thought to be due to a somatic mutation in phosphatidyl-inositol 3 kinase. It belongs to a group of syndromes termed the PI3CA-Related Overgrowth Spectrum (PROS) disorders. Because of the rarity and clinical heterogeneity of these disorders, management is patient specific, and best evidence guidelines are lacking. The most common clinical complications are thromboembolism, thrombophlebitis, pain, bleeding, and high-output heart failure. Surgery is recommended for hemangiomas and chronic venous insufficiency. The early identification of children with PROS disorders has allowed treatment with mTOR inhibitors which have been shown to be effective. The recent development of a direct PI3K inhibitor (alpelisib) has shown promise in preventing abnormal growth and long-term complications of KTS. This report documents a case of high-output heart failure due to the vascular malformations associated with KTS in a 57-year-old male patient and discusses current literature regarding the management of KTS with inhibitors of mTOR and PI3KCA.

Impact of the Syrian conflict and forced displacement on respiratory health: an analysis of primary data from a humanitarian organisation.

BACKGROUND: Despite a decade of conflict, there has been little exploration of respiratory health in Syria, notwithstanding the known impacts of conflict on lung health. Our aim is to explore the burden and trends of respiratory consultations in Syrian American Medical Society (SAMS) facilities in northwest Syria through an ecological analysis. METHODS: We performed a retrospective review of routinely collected data relating to respiratory presentations in SAMS' facilities between March 2017 and June 2020; we compared data by facility type, infectious versus non-infectious aetiologies and age. RESULTS: Data were available for 5 058 864 consultations, of which 1 228 722 (24%) were respiratory presentations, across 22 hospitals, 22 primary healthcare centres, 3 mobile clinics and 1 polyclinic. The median number of respiratory consultations per month was 30 279 (IQR: 25 792-33 732). Key findings include: 73% of respiratory consultations were for children; respiratory presentations accounted for up to 38% of consultations each month, seasonal variation was evident; respiratory tract infections accounted for 91% of all respiratory presentations. A steep decrease in consultations occurred between the end of 2019 (160 000) and the first quarter of 2020 (90 000), correlating with an escalation of violence in Idlib governorate. CONCLUSION: This study presents the largest quantitative analysis of respiratory data collected during the Syrian conflict. It supports the need for improved measures to aid the prevention, diagnosis and management of respiratory conditions during conflict as well as further research to explore the impact of conflict on respiratory health.

Bone intrinsic material and compositional properties in postmenopausal women diagnosed with long-term Type-1 diabetes.

The incidence of diabetes mellitus and the associated complications are growing worldwide, affecting the patients' quality of life and exerting a considerable burden on health systems. Yet, the increase in fracture risk in type 1 diabetes (T1D) patients is not fully captured by bone mineral density (BMD), leading to the hypothesis that alterations in bone quality are responsible for the increased risk. Material/compositional properties are important aspects of bone quality, yet information on human bone material/compositional properties in T1D is rather sparse. The purpose of the present study is to measure both the intrinsic material behaviour by nanoindentation, and material compositional properties by Raman spectroscopy as a function of tissue age and microanatomical location (cement lines) in bone tissue from iliac crest biopsies from postmenopausal women diagnosed with long-term T1D (N = 8), and appropriate sex-, age-, BMD- and clinically-matched controls (postmenopausal women; N = 5). The results suggest elevation of advanced glycation endproducts (AGE) content in the T1D and show significant differences in mineral maturity / crystallinity (MMC) and glycosaminoglycan (GAG) content between the T1D and control groups. Furthermore, both hardness and modulus by nanoindentation are greater in T1D. These data suggest a significant deterioration of material strength properties (toughness) and compositional properties in T1D compared with controls.

Smoke-induced signal molecules in bone marrow cells from altered low-density lipoprotein receptor-related protein 5 mice.

Mechanism underlying smoke-induced loss of bone mass is unknown. In this study, we hypothesized that protein signals induced by smoking in bone marrow may be associated with the loss of bone mass. Using a proteomics approach, we identified 38 proteins differentially expressed in bone marrow cells from low-density lipoprotein receptor-related protein 5 (Lrp5) mice exposed to cigarette smoking. Smoking effects on protein expression in bone marrow among three genotypes (Lrp5(+/+), Lrp5(G171V), and Lrp5(-/-)) varied. On the basis of the ratio of protein expression induced by smoking versus nonsmoking, smoke induced protein expression significantly in wild-type mice compared to the other two genotypes (Lrp5(G171V) and Lrp5(-/-)). These proteins include inhibitors of ß-catenin and proteins associated with differentiation of osteoclasts. We observed that S100A8 and S100A9 were overexpressed in human smokers compared to nonsmokers, which confirmed the effect of smoking on the expression of two proteins in Lrp5 mice, suggesting the role of these proteins in bone remodeling. Smoke induced expression of S100A8 and S100A9 in a time-dependent fashion, which was opposite of the changes in the ratio of OPG/RANKL in bone marrow cells, suggesting that the high levels of S100A8 and S100A9 may be associated with smoke-induced bone loss by increasing bone resorption.

Intrinsic material properties of trabecular bone by nanoindentation testing of biopsies taken from healthy women before and after menopause.

Postmenopausal osteoporosis in women is characterized by an increase in bone fragility and risk of fracture. In addition to transmenopausal decline in three-dimensional trabecular bone architecture, changes in intrinsic material properties (local stiffness, damping, and hardness) may contribute to increased bone fragility. In this study, nanoindentation was used to quantify transmenopausal changes in the intrinsic properties of trabecular bone. Paired transilial biopsy specimens were used from a previously reported study in which bone biopsies were obtained from women prior to menopause (premenopausal, age 49.0 ± 1.9) and at 12 months past the last menstrual period (postmenopausal, age 54.6 ± 2.2). Elastic and viscoelastic material properties of the trabecular bone were measured using quasi-static and dynamic nanoindentation techniques, respectively. Paired Student's t tests (n = 15) were performed to assess the significance of the measured intrinsic properties. Trabecular bone microarchitecture is compromised in postmenopausal women, and although this loss is associated with a trend toward reduction in some intrinsic properties (storage modulus), we found no statistically significant changes in bone intrinsic properties between healthy pre- and postmenopausal biopsies in the quasi-static results and frequency-averaged dynamic results.

Optimization of Monolayer MoS2 with Prescribed Mechanical Properties.

Various technological challenges are essentially material problems in our times. New functional and functional graded nanomaterials are constructed of components with predefined properties. The design of nanostructures with predefined mechanical properties was considered in this paper. This study applies the evolutionary algorithm (EA) to the optimization problem in the design of nanomaterials. The optimal design combined EA with molecular dynamics to identify the size of the void for the prescribed elastic properties in monolayer 2D MoS2 nanostructures. The numerical results show that the proposed EA and the use of optimization method allowed accurately obtaining nanostructures with predefined mechanical material properties by introducing elliptical voids in the 2D MoS2 nanosheets.

Ab initio study for superior sensitivity of graphyne nanoflake towards nitrogen halides over ammonia.

Graphyne (GYN) has received immense attention in gas adsorption applications due to its large surface area. The adsorption of toxic ammonia and nitrogen halides gaseous molecules on graphyne has been theoretically studied at ωB97XD/6-31 + G(d, p) level of DFT. The counterpoise corrected interaction energies of NH3, NF3, NCl3, and NBr3 molecules with GYN are - 4.73, - 2.27, - 5.22, and - 7.19 kcal mol-1, respectively. Symmetry-adapted perturbation theory (SAPT0) and noncovalent interaction index (NCI) reveal that the noncovalent interaction between analytes and GYN is dominated by dispersion forces. The significant change in electronic behavior, i.e., energies of HOMO and LUMO orbitals and NBO charge transfer correspond to the pronounced sensitivity of GYN towards considered analytes, especially NBr3. Finally, TD-DFT calculation reveals a decrease in electronic transition energies and shifting of adsorption to a longer wavelength. The recovery time for NX3@GYN is observed in nanoseconds, which is many orders of magnitude smaller than the reported systems. The recovery time is further decreased with increasing temperature, indicating that the GYN benefits from a short recovery time as a chemical sensor.

Remarkable non-linear optical properties of gold cluster doped graphyne (GY): A DFT study.

The nonlinear optical (NLO) properties of gold (Au) doped graphyne (GY) complexes are the subject of this quantum mechanical investigation. Detailed profiling of GY@Aucenter, GY@Auside, GY@2Auabove,GY@2Auperpendicular, and GY@3Aucenter is accomplished at CAM-B3LYP/LANL2DZ. The differential influence of various GY based complexes on molecular geometry, vertical ionization energy (VIE), interaction energy (Eint), frontier molecular orbitals (FMOs), density of states (DOS), absorption maximum (λmax), molecular electrostatic potential (MEP), electron density distribution map (EDDM), transition density matrix (TDM), dipole moment (µ) and non-linear optical (NLO) properties have been investigated. Non-covalent interaction (NCI) analysis has been done to explore the sort of interactions in designed complexes. The vibrational frequencies are probed via infrared (IR) analysis. Doping tactics in all complexes dramatically changed charge carrier properties, such as shrinking band gap (Eg) and increasing λmax in the range of 3.97-5.58 eV and 288-562 nm respectively, compared to pure GY with 5.78 eV Eg and 265 nm λmax. When compared to GY (αO = 281.54 andßO = 0.21 au), GY@3Aucenter exhibited a significant increase in static mean polarizability (αO = 415 au) and the mean first hyperpolarizability (ßo = 3652 au) attributable to its lowest excitation energy (ΔE). GY doping has been discovered to be advantageous for designing potential nanoscale devices by focusing on the symphony between small Au clusters and GY and their impacts on NLO aspects.

A pilot study on the nanoscale properties of bone tissue near lacunae in fracturing women.

The goal of this study is to investigate the causes of osteoporosis-related skeletal fragility in postmenopausal women. We hypothesize that bone fragility in these individuals is largely due to mineral, and/or intrinsic material properties in the osteocyte lacunar/peri-lacunar regions of bone tissue. Innovative measurements with nanoscale resolution, including scanning electron microscope (SEM), an atomic force microscope that is integrated with infrared spectroscopy (AFM-IR), and nanoindentation, were used to characterize osteocyte lacunar and peri-lacunar properties in bone biopsies from fracturing (Cases) and matched (Age, BMD), non-fracturing (Controls) postmenopausal healthy women. In the peri-lacunar space, the nanoindentation results show that the modulus and hardness of the Controls are lower than the Cases. The AFM-IR results conclusively show that the mineral matrix, maturity (peak) (except in outer/far regions in Controls) were greater in Controls than in Cases. Furthermore, these results indicate that while mineral-to-matrix area ratio tend to be greater, the mineral maturity and crystallinity peak ratio "near" lacunae is greater than at regions "far" or more distance from lacunae in the Controls only. Due to the heterogeneity of bone structure, additional measurements are needed to provide more convincing evidence of altered lacunar characteristics and changes in the peri-lacunar bone as mechanisms related to postmenopausal women and fragility. Such findings would motivate new osteocyte-targeted treatments to reduce fragility fracture risks in these groups.

Prospecting cellulose fibre-reinforced composite membranes for sustainable remediation and mitigation of emerging contaminants.

Many environmental pollutants caused by uncontrolled urbanization and rapid industrial growth have provoked serious concerns worldwide. These pollutants, including toxic metals, dyes, pharmaceuticals, pesticides, volatile organic compounds, and petroleum hydrocarbons, unenviably compromise the water quality and manifest a severe menace to aquatic entities and human beings. Therefore, it is of utmost importance to acquaint bio-nanocomposites with the capability to remove and decontaminate this extensive range of emerging pollutants. Recently, considerable emphasis has been devoted to developing low-cost novel materials obtained from natural resources accompanied by minimal toxicity to the environment. One such component is cellulose, naturally the most abundant organic polymer found in nature. Given bio-renewable sources, natural abundance, and impressive nanofibril arrangement, cellulose-reinforced composites are widely engineered and utilized for multiple applications, such as wastewater decontamination, energy storage devices, drug delivery systems, paper and pulp industries, construction industries, and adhesives, etc. Environmental remediation prospective is among the fascinating application of these cellulose-reinforced composites. This review discusses the structural attributes of cellulose, types of cellulose fibrils-based nano-biocomposites, preparatory techniques, and the potential of cellulose-based composites to remediate a diverse array of organic and inorganic pollutants in wastewater.

Protracted armed conflict and maternal health: a scoping review of literature and a retrospective analysis of primary data from northwest Syria.

INTRODUCTION: Syria's protracted conflict has devastated the health system reversing progress made on maternal health preconflict. Our aim is to understand the state of maternal health in Syria focused on underage pregnancy and caesarean sections using a scoping review and quantitative analysis; the latter draws on data from the Syrian American Medical Society's (SAMS) maternal health facilities in northwest Syria. METHODS: We performed a scoping review of academic and grey literature on the state of maternal health across Syria since the onset of conflict (taken as March 2011). Identified articles were screened using pre-established criteria and themes identified. We also performed a retrospective quantitative analysis of maternal health data from SAMS' facilities in a microcontext in north-west Syria between March 2017 and July 2020, analysing the trends in the proportion of births by caesarean section and age at pregnancy. RESULTS: Scoping review: of 2824 articles, 21 remained after screening. Main themes related to maternal mortality rates, caesarean sections, maternal age and perinatal care. 12 studies reported caesarean section rates; these varied from 16% to 64% of all births: northern Syria (19%-45%,) Damascus (16%-54%,) Lattakia (64%) and Tartous (59%.) Quantitative analysis: Of 77 746 births across 17 facilities, trend data for caesarean sections showed a decrease from 35% in March 2017 to 23% in July 2020 across SAMS facilities. Girls under 18 years accounted for 10% of births and had a lower proportion of caesarean section births. There was notable geographical and interfacility variation in the findings. CONCLUSION: The quality of available literature was poor with country-level generalisations. Research which explores microcontexts in Syria is important given the different effects of conflict across the country and the fragmented health system. Our quantitative analysis provides some evidence around the changes to caesarean section rates in northwest Syria. Despite limitations, this study adds to sparse literature on this important topic.

Intrinsic material properties of cortical bone.

The G171V mutation (high bone mass, HBM) is autosomal dominant and is responsible for high bone mass in humans. Transgenic HBM mice in which the human LRP5 G171V gene is inserted also show a similar phenotype with greater bone mass and biomechanical performance than wild-type mice, as determined by whole bone testing. Whole bone mechanics, however, depend jointly on bone mass, architecture, and intrinsic bone tissue mechanical properties. To determine whether the HBM mutation affects tissue-level biomechanical performance, we performed nano-indentation testing of unembedded cortical bone from HBM mice and their nontransgenic (NTG) littermates. Femora from 17-week-old mice (female, 8 mice/genotype) were subjected to nano-indentation using a Triboscope (Hysitron, Minneapolis, MN, USA). For each femoral specimen, approximately 10 indentations were made on the midshaft anterior surface with a target force of either 3 or 9 mN at a constant loading rate of 400 mN/s. The load-displacement data from each test were used to calculate indentation modulus and hardness for bone tissue. The intrinsic material property that reflected the bone modulus was greater (48%) in the HBM as compared to the NTG mice. Our results of intrinsic properties are consistent with the published structural and material properties of the midshaft femur in HBM and NTG mice. The greater intrinsic modulus in HBM reflects greater bone mineral content as compared to NTG (wild-type, WT) mice. This study suggests that the greater intrinsic property of cortical bone is derived from the greater bone mineral content and BMD, resulting in greater bone strength in HBM as compared to NTG (WT) mice.