Genotyping and pathogenic characterization of canine distemper virus based on mutations in the hemagglutinin gene in Chinese domestic dogs

Canine distemper virus (CDV) infects wild and domestic Canidae worldwide. The hemag- glutinin (H) gene has the highest genetic variation in the genome of this virus. Thus, the H gene is commonly used for lineage identification and genetic analyses. In order to study the genetic characteristics and pathogenicity of CDV strains prevalent in China, 132 samples were collected from domestic dogs with suspected CDV infection, 58 samples were confirmed to be positive, and the H gene was successfully amplified from 15 samples. The epidemic strain was identified as type Asia-1 and the novel mutations, A51T, V58I, R179K and D262N, were detected in this strain. Isolated strains, BJ16B53, BJ16B14, and BJ17B8, were used for an animal infection experiment in raccoon dogs. BJ16B53 and BJ16B14 were found to cause clinical symptoms, death, and exten- sive lesions in various organs. These results are expected to facilitate the development of effective strategies to monitor and control CDV infection in China.

Smart identification of psoriasis by images using convolutional neural networks: a case study in China

BACKGROUND

Psoriasis is a chronic inflammatory skin disease, which holds a high incidence in China. However, professional dermatologists who can diagnose psoriasis early and correctly are insufficient in China, especially in the rural areas. A smart approach to identify psoriasis by pictures would be highly adaptable countrywide and could play a useful role in early diagnosis and regular treatment of psoriasis.

OBJECTIVES

Design and evaluation of a smart psoriasis identification system based on clinical images (without relying on a dermatoscope) that works effectively similar to a dermatologist.

METHODS

A set of deep learning models using convolutional neural networks (CNNs) was explored and compared in the system for automatic identification of psoriasis. The work was carried out on a standardized dermatological dataset with 8021 clinical images of 9 common disorders including psoriasis along with full electronic medical records of patients built over the last 9 years in China. A two-stage deep neural network was designed and developed to identify psoriasis. In the first stage, a multilabel classifier was trained to learn the visual patterns for each individual skin disease. In the second stage, the output of the first stage was utilized to distinguish psoriasis from other skin diseases.

RESULTS

The area under the curve (AUC) of the two-stage model reached 0.981 ± 0.015, which outperforms a single-stage model. And, the classifier showed superior performance (missed diagnosis rate: 0.03, misdiagnosis rate: 0.04) than 25 Chinese dermatologists (missed diagnosis rate: 0.19, misdiagnosis rate: 0.10) in the diagnosis of psoriasis on 100 clinical images.

CONCLUSIONS

Using clinical images to identify psoriasis is feasible and effective based on CNNs, which also builds a solid technical base for smart care of skin diseases especially psoriasis using mobile/tablet applications for teledermatology in China.

P1499Data-driven clustering unveils the adaptive remodeling of athlete heart: an echocardiographic study from 2017 Taipei summer universiade

Background

Sport-specific adaptations of the athlete's heart are still under investigation. This study sought to provide a proof-of-concept for hierarchical clustering of echocardiography-derived parameters in unfolding the adaptations and to make a comparison between hypothesis-driven and data-driven approaches for characterizing the athlete's heart.

Methods

Anthropometric, echocardiographic and electrocardiographic assessments were collected during the peri-participation cardiovascular examination of 2017 Summer Universiade. Besides standard echocardiography and strain measurements, ventricular-arterial coupling was assessed by the ratio of effective arterial elastance (Ea) to left ventricular end-systolic elastance (Ees), using a modified single-beat algorithm to calculate Ees.

Results

A total of 598 elite athletes (348 male, mean age 23±2.5 years) engaged 24 disciplines were grouped by Mitchell's classification. The hypothesis-driven approach showed significant differences in heart rate, ventricular size, and stroke volume when classified by dynamic levels. Adaptations of ventricular function were not found. Contrarily, the data-driven approach not only hierarchically clustered athletes with more manifest morphologic remodeling, more proportions playing high dynamic sports but also showed a functional propensity of lower Ea and Ees, supranormal diastolic function and preserved ventricular-arterial coupling with ample pumping reserve.

Phenotype heatmaps of athletes

Conclusions

The hierarchical clustering can analyze numerous echocardiography-derived phenotypes pertaining to an individual athlete as well as discern an adaptive propensity of the athlete's heart to be the resting status of a reservoir-rich pump. This pilot demonstration of the data-driven approach in figuring out integrated physiologic adaptations with remodeling-relevant geometry and function leads to a fundamentally improved understanding of the athlete's heart and then will be applicable to various domains.

Successful implementation of bedaquiline for multidrug-resistant TB treatment in remote Papua New Guinea

SETTING

Bedaquiline (BDQ) was introduced in the multi-drug-resistant tuberculosis (MDR-TB) programme in Daru in remote Papua New Guinea in 2015, along with a core package of active drug-safety monitoring (aDSM).

OBJECTIVE

To assess interim results and safety of BDQ for the treatment of MDR-TB from 1 July 2015 to 31 December 2017.

DESIGN

A retrospective cohort analysis of routine programme data.

RESULTS

Of 277 MDR-TB patients, 77 (39%) received BDQ with a total of 8 serious adverse events including 5 (6.5%) deaths, of which 1 (1.3% QTcF prolongation, grade 3) was attributable to BDQ. Of 200 (61%) patients who did not receive BDQ, there were 17 (9%) deaths. Completeness of monitoring for the BDQ group was 90% for >5 electrocardiograms and 79% for ⩾2 cultures. In the interim result indicator analysis at month 6 in the BDQ and non-BDQ groups, there were respectively 0% and 1% lost to follow-up; 6.5% and 8.5% who died; 94% and 91% in care; and 92% and 96% with negative culture among those monitored.

CONCLUSION

Early experience in Daru shows BDQ is safe and feasible to implement with aDSM with good interim effectiveness supporting the rapid adoption and scale-up of the 2019 WHO MDR-TB treatment guidelines in the programme and in similar remote settings.

[Association between elective cesarean delivery and duration of breastfeeding in Ma'anshan City from 2013 to 2014]

Objective: To analyze the correlation between elective cesarean delivery and duration of breastfeeding in Ma'anshan city from 2013 to 2014. Methods: From May 2013 to September 2014, a total of 3 474 pregnant women with the first prenatal checkup were recruited from Ma'anshan maternal and child health care hospital. Finally, 3 109 pregnant women were included after exclusion of those with terminated pregnancies, adverse birth outcomes, twin or multiple pregnancies, breech traction, breech midwifery and loss of delivery information. Demographic data of pregnant women, mode of delivery and breast feeding of children were collected through questionnaires and hospital records. Logistic regression model was used to analyze the relationship between elective cesarean delivery and duration of breastfeeding in children, with the mode of delivery as independent variable and the duration of breastfeeding as dependent variable. Results: The age of 3 109 subjects was (26.6±3.6) years old, the rate of vaginal delivery was 51.1% (1 589), and the rate of elective cesarean delivery was 46.4% (1 443), among which the rate of non-indicative elective cesarean delivery was 26.4% (820), the rate of indicative elective cesarean delivery was 20.0% (623), and the rate of emergency cesarean delivery was 2.5% (77). The proportion of breastfeeding lasting until 4, 12 and 18 months was 45.0% (1 348/2 998), 23.7% (702/2 962) and 5.2% (154/2 944), respectively. After adjusting the confounding factors, compared with vaginal delivery, the OR (95%CI) values of breastfeeding for 4 months in indicative elective cesarean delivery and non-indicative elective cesarean delivery women were 0.870(0.714-1.059), 0.795(0.665-0.949), and the OR (95%CI) values of breastfeeding for 12 months were 0.772(0.611-0.975), 0.755(0.610-0.934), respectively. Conclusion: Elective cesarean delivery may result in shorter duration of breastfeeding in children.

Development of Arg-Based Biodegradable Poly(ester urea) Urethanes and Its Biomedical Application for Bone Repair

Thermal plastic polyurethanes (TPUs), serving as biomaterials, have become increasingly prevalent over time in many fields including artificial blood vessels, pericardial patches and other tissue engineering scaffolds by virtue of well adjustable performance. However, synthetic polyurethanes are, to some extent, inadequate for their cytocompatibility and biological activity owing to high hydrophobicity and lack of active groups. In this study, an amino-terminated bis(L-arginine) alkylene diester extender (L-Arg-8) was synthesized and Arg-based biodegradable poly(ester urea) urethanes (PEUUs) with different content of arginine groups were designed, synthesized and characterized in regard to the amelioration of the biodegradability, hydrophilicity and cytocompatibility of thermoplastic polyurethanes (TPUs) with PCL as soft segments. Biodegradability, hydrophilicity and positive surface charges increased after Arginine was introduced. As cytocompatibility was improved, PEUU materials A8-1.2 and A8-1.6 were proved to be suitable for human dental pulp stem cells (hDPSCs) to adhere, grow and proliferate on in vitro. These materials would unlock great potential for the use in tissue engineering and regeneration. Additionally, halloysite nanotubes (HNTs) were composited to PEUUs for further exploration to the applications in bone tissue. The addition of halloysite nanotubes further stimulated the osteogenic differentiation of human dental pulp stem cells in vitro. At the same time, a rat cranial defect model was built to assess effects of repair in vivo. Osteointegration and repair were promoted by patch-implanted groups. A8-1.2 6% HNTs showed the best repair. All the results indicated that Arg-based poly(ester urea) urethanes and the composites were conductive to bone repair.

[Placental microbiota and pregnancy]

The role of microbes in regulating the metabolism and immune function of the body has been highlighted. The interactions of host-microbe and microbial-microbe have existed before the birth. However, the existence of placental microbiota and their regulatory effects on pregnancy are still controversial. It was found that placental microbes might be implanted into the placenta via urogenital-placental, gastrointestinal-placental, and oral-placental routes. Microbiome may play a role in promoting the outcome of benign pregnancy, and the placental microbiota in pathological pregnancy may be associated to adverse pregnancy outcome. Placenta and amniotic fluid microbes have been linked to abortion, chorioamnionitis, premature rupture of membranes, premature delivery and stillbirth in Cultivation-dependent and Cultivation-independent studies. Obesity, gestational diabetes mellitus, probiotics and antibiotics during pregnancy may be the main factors affecting placenta microbiology.

Modulation of intestinal microbiota by glycyrrhizic acid prevents high-fat diet-enhanced pre-metastatic niche formation and metastasis

High-fat diet (HFD) promotes lung pre-metastatic niche formation and metastasis. Thus, there is an urgent need to identify the underlying mechanisms and develop strategies to overcome them. Here we demonstrate that glycyrrhizic acid (GA) prevents HFD-enhanced pre-metastatic niche formation and metastasis through gut microbiota. GA reduced HFD-enhanced myeloid-derived suppressor cell recruitment, pro-metastatic protein S100A8/A9 expression and metastasis burden of 4T1 breast cancer and B16F10 melanoma, accompanied by gut microbiota alteration and colonic macrophage polarization far away the M1-like phenotype. These parameters were greatly decreased by treatment with antibiotics, recolonization of Desulfovibrio vulgaris and Clostridium sordellii, and administration of lipopolysaccharide or deoxycholic acid. Macrophage depletion attenuated HFD-enhanced pre-metastatic niche formation and metastasis, but failed to further affect the effects of GA. Mechanistically, counteraction of HFD-enhanced gut microbiota dysbiosis by GA inhibited Gr-1⁺ myeloid cell migration and S100A8/A9 expression through decreasing the proportion of M1-like macrophages and their production of CCL2 and TNF-α in the colons via LPS/HMGB1/NF-κB signaling inactivation. Together, targeting the gut microbiota by GA to modulate colonic macrophages could be a novel strategy for the prevention of HFD-enhanced pre-metastatic niche formation and metastasis.

[Cumulative risk assessment of phthalates exposure in preschool children]

Objective: The urine concentrations of phthalate metabolites were used to estimate the cumulative risk assessment in preschool children in Ma'anshan of Anhui province. Methods: Based on the China-Anhui Birth Cohort, the demographic information and urine samples of 3 743 children were collected in Ma'anshan from April 2014 to April 2015. The concentrations of 7 metabolites' [monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono (2-ethylhexyl) phthalate (MEHP), mono (2-ethyl- 5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP)] of 5 phthalates [dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBzP), and di (2-ethylhexyl) phthalate (DEHP)] in the urine samples of the children were measured by solid-phase extration-triple quadrupole high performance liquid chromatography-tandem mass spectrometry-isotope method. In addition, the estimated daily intakes (EDIs) of 5 phthalates were calculated according to the metabolites' concentrations. Cumulative risk assessment was performed using hazard quotient (HQ) and hazard index (HI) methods. Results: The M (Q(R)) of seven metabolite concentrations were 29.58 (18.69-48.26), 26.65 (13.44-56.09), 256.86 (150.99-438.51), 0.12 (0.04-0.32), 6.27 (3.71-11.13), 17.94 (11.94-28.42) and 24.80 (16.05-40.32) μg/g creatinine, respectively. For the EDIs of 5 phthalates, DBP ranked first, followed by DEHP, DMP, DEP and BBzP with the M (Q(R)) of 7.54 (4.41-12.85), 3.35 (2.20-5.42), 0.75 (0.47-1.24), 0.71 (0.36-1.52) and 0.003 (0.001-0.009) μg/(kg·d), respectively. The HQ and HI varied with age, gender and sampling season, the differences were significant (P<0.05). Conclusions: These results indicated that risk of cumulative exposure to phthalates was high in preschool children aged 3-6 years in Ma'anshan. Age, gender and sampling season were influencing factors.

Gelatin methacryloyl (GelMA)-based biomaterials for bone regeneration

Gelatin methacryloyl (GelMA)-based biomaterials have been widely used in various biomedical applications due to their suitable biological properties and tuneable physical characteristics. In particular, GelMA can be used as a versatile matrix for bone tissue engineering scaffolds via various strategies to overcome major obstacles such as insufficient mechanical property and uncontrollable degradation. This review presents the research status of GelMA, its structure and function, GelMA-based biomaterials and the development of methods along with their existing challenges.

Double-Layer Microsphere Incorporated with Strontium Doped Calcium Polyphosphate Scaffold for Bone Regeneration

To design and prepare a novel controlled release system for sustained release of two drugs. In this study, a double-layer microsphere was incorporated with strontium-doped calcium polyphosphate (SCPP) scaffold to facilitate bone regeneration and achieve skull repair. The double-layer microsphere combining tetracycline loaded sodium alginate and matrix metalloproteinase-2 (MMP-2) loaded chitosan was manufactured by electrospinning, which were further adhered to SCPP scaffold. The characteristics of microstructure were observed through scanning electron microscope. Loading efficiencies and the optimal ratio of microsphere of the obtained controlled release system were investigated. In addition, the cytotoxicity and the effects on osteoblast proliferation and expressions of osteogenesis-related factors were examined in vitro. Thereafter, the compound material with the controlled release system was implanted in the skull defect of rabbit to evaluate its properties of promoting bone regeneration. The results indicated that this novel controlled release system with SCPP scaffold and the double-layer microspheres loaded with tetracycline and MMP-2 could be a promising material for bones repair.

A novel cage for actinides: A 6W4Al43 (A = U and Pu)

We report on synthesis and characterization of the compounds A ₆W₄Al₄₃ (A  =  U and Pu), that form in the hexagonal Ho₆Mo₄Al₄₃ caged-structure family. The A ions reside within W/Al cages where the A-A nearest neighbors form dimers between adjacent W/Al cages, with U-U and Pu-Pu distances of 3.3892 [Formula: see text] and 3.4080 [Formula: see text], respectively. While the W/Al networks provide environments similar to those of other cage-like materials (e.g. filled skutterudites), the atomic displacement parameters from single crystal x-ray diffraction measurements show that the A-ions do not exhibit rattling behavior. We find that there is site interchange disorder on one of the W/Al sites. Magnetic susceptibility measurements show that U₆W₄Al₄₃ displays anisotropic Curie-Weiss behavior where it fits to the data yield an effective magnetic moment near 2.0 [Formula: see text]/U. At low temperatures the magnetic susceptibility deviates from the Curie-Weiss temperature dependence and eventually saturates to a constant value. In contrast, Pu₆W₄Al₄₃ displays nearly temperature independent Pauli paramagnetism for all temperatures, as would be expected if the 5f -electrons are delocalized. The electrical resistivity for U₆W₄Al₄₃ increases slightly with the decreasing temperature, suggesting that it is dominated by f -electronic hybridization effects and disorder scattering that originates from the W/Al site interchange. Specific heat measurements for U₆W₄Al₄₃ further reveal an enhanced electronic Sommerfeld coefficient that is consistent with a moderately enhanced charge carrier effective mass. Together these measurements expose these materials as hosts for unstable f -electron magnetism, where the novel cage-like structures control the phenomena through the spacing between the A ions. Through this combination of mild magnetism, the low cost elements of the Al-W cages, and chemical tunability that has been shown for related materials in the same structure, the A ₆W₄Al₄₃ compounds emerge as promising nuclear waste-forms for transuranics, while the wider family of materials makes an appealing environment for studying f -electron physics in a novel structure.

[The relationship of maternal and umbilical cord blood zinc level associated with newborn birth weight: a birth cohort study]

Objective: To study serum zinc level in pregnancy and umbilical cord blood and their association with newborn birth weight. Methods: Pregnant women accepting obstetric examination in Ma'anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. The follow up was conducted during their first, second and third trimesters of pregnancy and the self-designed questionnaire was used to collect information of social and demographic characteristics. Blood samples in the first, second pregnancy period and umbilical cord blood samples were collected and serum concentrations of zinc were assayed. 3 239 mother-infant entered the final analysis. We divided serum zinc level into low (<P(25)), medium (P(25)-P(75)) and high (>P(75)) groups according to their exposure concentrations at each trimesters. Non-conditional multivariate logistic regression model was conducted to evaluate the association between serum zinc level in first, second trimesters of pregnancy and umbilical cord blood with small for gestational age (SGA) and large for gestational age (LGA). Results: Serum zinc level in P(50) (P(25)-P(75)) during the first, second trimesters and cord blood were 1 016.18 (907.09-1 145.60), 813.36 (732.47-897.89) and 903.44 (808.71-1 015.64) μg/L, respectively. The prevalence of zinc deficiency during the first, second trimesters and cord blood were 1.5% (44/2 957), 15.9% (492/3 087) and 6.5% (176/2 707), respectively. The prevalence of total SGA and LGA were 9.7% (313/3 239) and 16.5% (536/3 239), respectively. Compared to high-level serum zinc group, the risk of SGA (OR (95%CI) in low-level serum zinc group during first trimesters was 1.51 (1.05-2.19)). Serum zinc level among second pregnancy period and umbilical cord blood had no statistically significant effect on SGA and LGA (both P values >0.05). Conclusion: Zinc nutritional status of pregnant women in Ma'anshan city was at a good level. The low serum zinc level in first trimester increased the risk of SGA.

Glabridin Prevents Doxorubicin-Induced Cardiotoxicity Through Gut Microbiota Modulation and Colonic Macrophage Polarization in Mice

The chemotherapeutic drug doxorubicin (DOX) provokes a dose-related cardiotoxicity. Thus, there is an urgent need to identify the underlying mechanisms and develop strategies to overcome them. Here we demonstrated that glabridin (GLA), an isoflavone from licorice root, prevents DOX-induced cardiotoxicity through gut microbiota modulation and colonic macrophage polarization in mice. GLA reduced DOX-induced leakage of myocardial enzymes including aminotransferase, creatine kinase, lactate dehydrogenase, and creatine kinase-MB. GLA downregulated pro-apoptotic proteins (Bax, cleaved-caspase 9 and cleaved-caspase 3) and upregulated anti-apoptotic proteins (HAX-1 and Bcl-2) in the cardiac tissues. In addition, GLA modulated DOX-induced dysbiosis of gut microbiota and thereby decreased the ratio of M1/M2 colonic macrophage, accompanied by the downregulated lipopolysaccharide (LPS) and upregulated butyrate in the feces and peripheral blood. The leakage of myocardial enzymes induced by the DOX was decreased by antibiotics treatment, but not altered by co-treatment with the GLA and antibiotics. The ratio of M1/M2 colonic macrophage and leakage of myocardial enzymes reduced by the GLA were greatly increased by the Desulfovibrio vulgaris or LPS but decreased by the butyrate. Depletion of the macrophage attenuated DOX-induced cardiotoxicity but failed to further affect the effects of GLA. Importantly, GLA decreased production of M1 cytokines (IL-1β and TNF-α) but increased production of M2 cytokines (IL-10 and TGF-β) in the colonic macrophage with the downregulation of NF-κB and the upregulation of STAT6. In summary, GLA prevents DOX-induced cardiotoxicity through gut microbiota modulation and colonic macrophage polarization, and may serve as a potential therapeutic strategy for the DOX-induced cardiotoxicity.

[The associations between nighttime sleep duration, bedtime and preschool children's obesity]

Objective: To examine the relationship of nighttime sleep duration and bedtime with preschool children's obesity, and to explore possible early life risk factors for childhood obesity. Methods: A total of 14 946 valid children from 16 439 pre-school children aged 3-6 years in 91 kindergartens in Ma'anshan city participated in the study. The body mass index cut-offs for overweight and obesity in Chinese children and adolescents aged 2-18 years was used as the criterion for judging overweight and obesity, and pathological and secondary causes of obesity were excluded. The associations of nighttime sleep duration and bedtime with preschool children's obesity was analyzed by using non-conditional multivariate binary logistic regression model. Results: Among the preschool children, 22.4% (n=3 345) had shorter sleep duration. 9.5% (n=1 415) had bedtimes after 22:00 on weekdays and 21.8% (n=3 260) had bedtimes after 22:00 on weekends. The prevalence of overweight and obesity were 16.5% (n=2 466) and 10.5% (n=1 562), respectively. After the adjustent of age, gender, whether or not only child, residence in the last six months, parents' body mass index parents' educational level, diet preference, outdoor activities, TV viewing duration, sleep duration, bedtime on weekdays and weekends, only the shorter sleep duration (OR=1.25, 95%CI: 1.03-1.51) was still positively associated with the prevalence of obesity in preschool children. Conclusion: Shorter sleep duration was positively associated with the prevalence of obesity among preschool children.

[Effect of breastfeeding on the behavioral development of infants and children: a birth cohort study in Ma'anshan]

Objective: To discuss the relationship between breastfeeding and the behavioral development of infants and children. Methods: Based on the Ma'anshan Birth Cohort Study, there were 3 474 pregnant women recruited from Ma'anshan Maternal and Child Care Center between May 2013 and September 2014, including 3 273 singleton live births. Follow up the infants to the age of 18 months old. Excluded the infants with incomplete information of breastfeeding and who did not finish the ASQ-3 evaluation in 6 months old and 18 months old, 2 404 valid subjects were included in the study. The information of demographic characteristics, deliver, infants and breastfeeding was collected. The behavioral development were evaluated by the third edition of Ages and Stages Questionnaire (ASQ-3) at 6 months old and 18 months old, and the effect of breastfeeding on behavioral development among infants and children were analyzed by multivariable logistic regression model. Results: The intensity of breastfeeding of infants within 6 months old was (26.56±10.56). The rate of breastfeeding as pure or major intake for infants between 0-5 months old were separately 54.2% (1 303), 54.0% (1 298). 54.0% (1 297), 50.5% (1 213), 34.4% (827) and 9.9% (237). After age, pre-pregnant BMI, intelligence, delivery mode, gender, gestational age, birth weight and family economic status adjusted, compared to never-breastfeeding, continuous breastfeeding for 1-3 months could protect children from severe developmental delay in fine motor domain aged 6 months old (RR=0.36, 95%CI: 0.17-0.79), communication domain aged 18 months old (RR=0.27, 95%CI: 0.08-0.88), and social domain aged 18 months old (RR=0.36, 95%CI: 0.21-0.63). Compared to never-breastfeeding, continuous breastfeeding for more than 4 months could protect children from severe developmental delay in fine motor domain aged 6 months old (RR=0.58, 95%CI: 0.34-0.97), communication domain (RR=0.57, 95%CI: 0.39-0.83) and mild developmental delay (RR=0.65, 95%CI: 0.48-0.87) aged 18 months old and fine motor domain (RR=0.57, 95%CI: 0.39-0.83) aged 18 months old and social domain aged 18 months old (RR=0.57, 95%CI: 0.39-0.83). With the breastfeeding intensity rising, there were less children evaluated as severe development delay in communication domain aged 6 months old, communication, fine motor and problem-solving domains aged 18 months old, with RR (95%CI) at 0.98 (0.96-1.00), 0.96 (0.93-0.99), 0.98 (0.97-1.00) and 0.98 (0.96-1.00); and less children evaluated as mild development delay in communication domain aged 18 months old with RR (95%CI) at 0.99 (0.98-1.00). Conclusion: Breastfeeding with longer duration and increased intensity could promote better development in children.

Black Phosphorus Hydrogel Scaffolds Enhance Bone Regeneration via a Sustained Supply of Calcium-Free Phosphorus

Effective bone regeneration remains a challenge for bone-tissue engineering. In this study, we propose a new strategy to accelerate bone regeneration via a sustained supply of phosphorus without providing foreign calcium. Herein, a black phosphorus nanosheet (BPN)-based hydrogel platform was developed, and the BPNs were used to stably and mildly provide phosphorus. The hydrogel was fabricated by photo-crosslinking of gelatin methacrylamide, BPNs, and cationic arginine-based unsaturated poly(ester amide)s. This platform combines the following advantages: the hydrogel scaffold would keep BPNs inside, and the encapsulated BPNs can degrade into phosphorus ions and capture calcium ions to accelerate biomineralization in a bone defect. The introduction of BPNs helped to enhance the mechanical performance of hydrogels, photoresponsively release phosphate, and accelerate mineralization in vitro. Moreover, BPN-containing hydrogels improved osteogenic differentiation of human dental pulp stem cells via the bone morphogenic protein-runt-related transcription factor 2 pathway. In vivo results from a rabbit model of bone defects revealed that the BPNs helped to accelerate bone regeneration. All these results strongly suggest that the strategy of a sustained supply of calcium-free phosphorus and this BPN-containing hydrogel platform hold promise for effective bone regeneration.