[Research advances on the application of natural and recombinant collagen in wound repair]

Collagen is a macromolecular protein constituting the extracellular matrix of animal connective tissue, which has been widely used and developed in fields of biomedicine, tissue engineering, food, and cosmetics. Due to its advantages such as abundant sources and good biocompatibility, low immunogenicity, and degradability, collagen can be used as a dressing or tissue engineering scaffold for wound repair. According to the source of materials, collagen can be divided into natural collagen and recombinant collagen. Natural collagen is mainly extracted directly from mammals and fish; recombinant collagen is obtained based on genetic engineering technology, and its sources include recombinant expression systems of microorganisms, animals, and plants. This paper summarizes the sources of collagen, and the roles, advantages, and disadvantages of different sources of collagen in wound repair, the particularity and superiority of collagen combined with three-dimensional printing technology in wound repair, the impact of market norms of China's collagen industry on the field of wound repair, and explains the precautions for the development of collagen-related products, aiming to provide new ideas for selecting a suitable source of collagen for wound repair.

A novel cell line panel reveals non-genetic mediators of platinum resistance and phenotypic diversity in high grade serous ovarian cancer

OBJECTIVES

Resistance to cancer therapy is an enduring challenge and accurate and reliable preclinical models are lacking. We interrogated this unmet need using high grade serous ovarian cancer (HGSC) as a disease model.

METHODS

We created five in vitro and two in vivo platinum-resistant HGSC models and characterised the entire cell panel via whole genome sequencing, RNASeq and creation of intraperitoneal models.

RESULTS

Mutational signature analysis indicated that platinum-resistant cell lines evolved from a pre-existing ancestral clone but a unifying mutational cause for drug resistance was not identified. However, cisplatin-resistant and carboplatin-resistant cells evolved recurrent changes in gene expression that significantly overlapped with independent samples obtained from multiple patients with relapsed HGSC. Gene Ontology Biological Pathways (GOBP) related to the tumour microenvironment, particularly the extracellular matrix, were repeatedly enriched in cisplatin-resistant cells, carboplatin-resistant cells and also in human resistant/refractory samples. The majority of significantly over-represented GOBP however, evolved uniquely in either cisplatin- or carboplatin-resistant cell lines resulting in diverse intraperitoneal behaviours that reflect different clinical manifestations of relapsed human HGSC.

CONCLUSIONS

Our clinically relevant and usable models reveal a key role for non-genetic factors in the evolution of chemotherapy resistance. Biological pathways relevant to the extracellular matrix were repeatedly expressed by resistant cancer cells in multiple settings. This suggests that recurrent gene expression changes provide a fitness advantage during platinum therapy and also that cancer cell-intrinsic mechanisms influence the tumour microenvironment during the evolution of drug resistance. Candidate genes and pathways identified here could reveal therapeutic opportunities in platinum-resistant HGSC.

Na/K-ATPase suppresses LPS-induced pro-inflammatory signaling through Lyn

Na/K-ATPase (NKA), besides its ion transporter function, is a signal transducer by regulating Src family kinases (SFK). The signaling NKA contributes to oxidized LDL-induced macrophage foam cell formation and interacts with TLR4. However, its role in lipopolysaccharides (LPS)-induced signaling and glycolytic switch in macrophages remains unclear. Using peritoneal macrophages from NKA α1 haploinsufficient mice (NKA α1+/-), we found that NKA α1 haploinsufficiency led to enhanced LPS-stimulated NF-κB pathway, ROS signaling, and pro-inflammatory cytokines. Intraperitoneal injection of LPS resulted in more severe lung inflammation and injury with lower survival rate in NKA α1+/- mice. Additionally, LPS induced a higher extent of the metabolic switch from oxidative phosphorylation to glycolysis. Mechanistically, NKA α1 interacted with TLR4 and Lyn. The presence of NKA α1 in this complex attenuated Lyn activation by LPS, which subsequently restricted the downstream ROS and NF-κB signaling. In conclusion, we demonstrated that NKA α1 suppresses LPS-induced macrophage pro-inflammatory signaling through Lyn.

First Measurement of the Z→μ^{+}μ^{-} Angular Coefficients in the Forward Region of pp Collisions at sqrt[s]=13 TeV

The first study of the angular distribution of μ^{+}μ^{-} pairs produced in the forward rapidity region via the Drell-Yan reaction pp→γ^{*}/Z+X→ℓ^{+}ℓ^{-}+X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1  fb^{-1}. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the Z-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton.

Reclamation in southern China: The early Chu's agriculture revealed by macro-plant remains from the Wanfunao site (ca. 1000-770 BCE)

The Wanfunao site was a large Chu settlement in Zhou Dynasty. It was located on an alluvial plain along the Yangtze River in the Yichang section. The region around the site comprised mountains, hills, and plains, which was a compatible environment for the cultivation of various crops. Previous studies have suggested that the middle and lower reaches of the Yangtze River are one of the most productive regions for rice cultivation. Besides rice, however, seven dryland crops have been found at the Wanfunao site: foxtail millet, broomcorn millet, wheat, barley, oat, buckwheat, and adzuki bean. Among them, foxtail millet and rice are most ubiquitous. The crop assemblage has revealed that the northern dryland crops, including those were newly adapted cereals such as foxtail millet, wheat, and barley, gradually dispersed southward and became a part of the diet along with rice. This can be attributed to southern Chinese inhabitants' reclamation of the hilly environment for agriculture. Although communities in southern China had cultivated rice on the plains for thousands of years, newly introduced dryland crops from north China adapted to mountainous environments better. The development of multi-cropping systems in southern China likely involved changes in agricultural ontology associated with the adaptation of northern crops in southern environments newly encountered. Additionally, the assemblage of foxtail millet grain/rice spikelet base in the site may have been used for livestock feeding. A wide range of landforms, compatible farming, and surplus agricultural products for husbandry may have been a part of the economic foundation that facilitated the rise of Chu.

Non-invasive prediction of p53 and Ki-67 labelling indices and O-6-methylguanine-DNA methyltransferase promoter methylation status in adult patients with isocitrate dehydrogenase wild-type glioblastomas using diffusion-weighted imaging and dynamic susceptibility contrast-enhanced perfusion-weighted imaging combined with conventional MRI

AIM

To assess whether conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) could non-invasively predict p53 and Ki-67 labelling index (LI) and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in adult isocitrate dehydrogenase (IDH) wild-type glioblastomas.

METHODS

The conventional MRI, DWI, and DSC-PWI results of 120 adult patients with IDH wild-type glioblastomas were reviewed retrospectively and their efficacy was analysed using chi-square tests or Fisher's exact test. Relative minimum apparent diffusion coefficient (rADCmin) and relative maximum cerebral blood volume (rCBVmax) values were compared between glioblastomas with different molecular statuses using the Mann-Whitney U-test. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate predictive performance.

RESULTS

Glioblastomas with a high p53 LI were more likely to show a well-defined enhancement margin (p=0.047). Glioblastomas in the high-Ki-67-LI group demonstrated significantly lower rADCmin (p<0.001) and higher rCBVmax (p=0.001) values than those in the low-Ki-67-LI group. Tumours without MGMT promoter methylation showed lower rADCmin (p<0.001) and higher rCBVmax (p<0.001) values than those with it. The rCBVmax value exhibited a greater efficacy in predicting the MGMT promoter methylation status of adult IDH wild-type glioblastomas than the rADCmin value (p=0.001).

CONCLUSIONS

The present results suggest that conventional and DWI and DSC-PWI results are influenced by the molecular status of the glioblastoma and indicate that DWI and DSC-PWI may help to identify regions of high invasiveness within heterogeneous glioblastomas.

[Patient experience in the implementation of enhanced recovery after surgery strategy after radical gastric cancer surgery]

Objective: To investigate the experience of patients in the implementation of enhanced recovery after surgery (ERAS) strategy after radical gastrectomy and the factors affecting the treatment experience. Methods: A prospective cohort study was carried out. Patients who were diagnosed with gastric cancer by pathology and underwent radical gastrectomy at the Xijing Digestive Disease Hospital from December 2019 to December 2020 were consecutively enrolled. Those who received emergency surgery, residual gastric cancer surgery, preoperative neoadjuvant chemotherapy, non-curative tumor resection, intraperitoneal metastasis, or other malignant tumors were excluded. Patients' expectation and experience during implementation were investigated by questionnaires. The questionnaire included three main parts: patients' expectation for ERAS, patients' experience during the ERAS implementation, and patients' outcomes within 30 days after discharge. The items on the expectation and experience were ranked from 0 to 10 by patients, which indicated to be unsatisfied/unimportant and satisfied/important respectively. According to their attitudes towards the ERAS strategy, patients were divided into the support group and the reject group. Patients' expectation and experience of hospital stay, and the clinical outcomes within 30 days after discharge were compared between the two groups. Categorical data were reported as number with percentage and the quantitative data were reported as mean with standard deviation, or where appropriate, as the median with interquartile range (Q₁, Q₃). Categorical data were compared using the Chi-squared test or Fisher's exact test, where appropriate. For continuous data, Student's t test or Mann-Whitney U test were used. Complication was classified according to Clavien-Dindo classification. Results: Of the included 112 patients (88 males and 24 females), aged (57.8±10.0) years, 35 patients (31.3%) were in the support group and 77 (68.7%) in the reject group. Anxiety was detected in 56.2% (63/112) of the patients with score >8. The admission education during the ERAS implementation improved the patients' cognitions of the ERAS strategy [M(Q₁, Q₃) score: 8 (4, 10) vs. 2 (0, 5), Z=-7.130, P<0.001]. The expected hospital stay of patients was longer than the actual stay [7 (7, 10) days vs. 6 (6, 7) days, Z=-4.800, P<0.001]. During the ERAS implementation, patients had low score in early mobilization [3 (1, 6)] and early oral intake [5 (2.25, 8)]. Fifty-eight (51.8%) patients planned the ERAS implementation at home after discharge, while 32.1% (36/112) preferred to stay in hospital until they felt totally recovered. Compared with the reject group, the support group had shorter expected hospital stay [7 (6, 10) days vs. 10 (7, 15) days, Z=-2.607, P=0.009], and higher expected recovery-efficiency score [9 (8, 10) vs. 7(5, 9), Z=-3.078, P=0.002], lower expected less-pain score [8 (6, 10) vs. 6 (5, 9) days, Z=-1.996, P=0.046], expected faster recovery of physical strength score [8 (6, 10) vs. 6 (4, 9), Z=-2.200, P=0.028] and expected less drainage tube score [8 (8, 10) vs. 8 (5, 10), Z=-2.075, P=0.038]. Worrying about complications (49.1%) and self-recognition of not recovery (46.4%) were the major concerns when assessing the experience toward ERAS. During the follow-up, 105 patients received follow-up calls. There were 57.1% (60/105) of patients who experienced a variety of discomforts after discharge, including pain (28.6%), bloating (20.0%), nausea (12.4%), fatigue (7.6%), and fever (2.9%). Within 30 days after discharge, 6.7% (7/105) of patients developed Clavien-Dindo level I and II operation-associated complications, including poor wound healing, intestinal obstruction, intraperitoneal bleeding, and wound infection, all of which were cured by conservative treatment. There were no complications of level III or above in the whole group after surgery. Compared with the support group, more patients in the reject group reported that they had not yet achieved self-expected recovery when discharged [57.1% (44/77) vs. 22.9% (8/35), χ²=11.372, P<0.001], and expected to return to their daily lives [39.0% (30/77) vs. 8.6% (3/35), χ²=10.693, P<0.001], with statistically significant differences (all P<0.05). Only 52.4% (55/105) of patients returned home to continue rehabilitation, and the remaining patients chose to go to other hospitals to continue their hospitalization after discharge, with a median length of stay of 7 (7, 9) days. Compared with the reject group, the support group had a higher proportion of home rehabilitation [59.7% (12/33) vs. 36.4% (43/72), χ²=4.950, P=0.026], and shorter time of self-perceived postoperative full recovery [14 (10, 20) days vs. 15 (14, 20) days, Z=2.100, P=0.036], with statistically significant differences (all P<0.05). Conclusions: Although ERAS has promoted postoperative rehabilitation while ensuring surgical safety, it has not been unanimously recognized by patients. Adequate rehabilitation education, good analgesia, good physical recovery, and early removal of drainage tubes may improve the patient's experience of ERAS.

Onboard spectral calibration and validation of the satellite calibration spectrometer on HY-1C

To monitor the spectral position drift, expansion and contraction of the full width at half maximum (FWHM) of the satellite calibration spectrometer (SCS) of the HY-1C satellite during on-orbit operation, an onboard spectral calibration method based on a wavelength diffuser is proposed in this paper. This method uses the wavelength diffuser reflectance measured prelaunch as the standard spectrum, convolves it with the spectral response function of the SCS to obtain a reference spectrum, uses the measured data of the onboard SCS as the measured spectrum, and obtains the spectral drift and variation of the FWHM through spectral line matching. Generally, the spectral response function of a hyperspectral remote sensor follows a Gaussian model, and so does that of the SCS. The spectral calibration results obtained based on the onboard wavelength diffuser are validated and evaluated in comparison to calibration based on an oxygen absorption line. Preliminary results show that (1) the SCS spectral drift is negative, indicating a shift in the shortwave direction, and its absolute value is gradually decreasing with increasing on-orbit operation time; (2) the mean values of the central wavelength and FWHM errors between the two calibration methods are 0.08 nm and 0.20 nm, respectively, indicating that the spectral calibration method based on the wavelength diffuser has high accuracy and reliability; and (3) the SCS spaceborne spectral calibration error has the greatest impact on radiometric calibration in Band 18, with an uncertainty of 0.99%, while the uncertainty in the other bands is less than 0.33%, indicating that the spectral calibration uncertainty meets radiometric calibration accuracy requirements.

[Impact of exposure to ambient fine particulate matter-bound polycyclic aromatic hydrocarbons on blood thrombogenicity in adults]

Objective: To investigate the effects of exposure to ambient fine particulate matter-bound polycyclic aromatic hydrocarbons on blood coagulation in adults. Methods: A total of 73 adult volunteers were recruited in a cohort study and had four clinical visits from November 2014 to January 2016. Blood samples were obtained and used to measure biomarkers of blood thrombogenicity, including soluble CD40 Ligand (sCD40L), soluble P-selection (sCD62P) and Fibrinogen (FIB). White blood cell (WBC), 8-Hydroxy-2'-Deoxyguanosine (8-OHdG), matrix metalloproteinase-2 (MMP-2) and HDL cholesterol efflux capacity (HDL-CEC) were also determined. Daily concentrations of ambient fine particulate matter-bound polycyclic aromatic hydrocarbons (PAHs) were measured throughout the study period, and positive matrix factorization (PMF) approach was used to identity PAHs sources. Linear mixed-effect models including single-pollutant model, two-pollutant model and stratification analysis were constructed to estimate the effects of exposure to ambient fine particulate matter-bound PAHs on blood thrombogenicity in adults after adjusting for potential confounders. Results: The mean age of participants was (23.3±5.4) years. During the study period, the median level of PM_2.5-bound PAHs was (55.29±74.99) ng/m³. Six sources of PM_2.5-bound PAHs were identified by PMF, with traffic sources contributing more than 50%. The linear mixed-effect model showed that PAHs exposure had a significant effect on elevated blood thrombogenicity. Significant elevations in sCD40L, sCD62P and FIB associated with per IQR increase (60.33 ng/m³) in exposure to PAHs were 14.36% (95%CI:6.94%-22.28%), 9.33% (95%CI: 1.71%-17.51%) and 2.07% (95%CI:0.44%-2.07%) at prior 5 days, respectively. Blood thrombogenicity levels were significantly and positively correlated with source-specific PAHs, especially gasoline vehicle emissions, diesel vehicle emission and coal burning at prior 1 or 5 days. Stronger associations between PAHs and increased blood thrombogenicity were found in participants with high plaque vulnerability, reduced HDL function, and high levels of inflammation and oxidative stress. Conclusion: Acute exposure to ambient fine particulate matter-bound PAHs, especially PAHs from traffic sources may promote blood thrombogenicity in adults, and PAHs have stronger effects on participants with reduced vascular function and high levels of inflammation and oxidative stress.

Complementary Data Augmentation for Cloth-Changing Person Re-Identification

This paper studies the challenging person re-identification (Re-ID) task under the cloth-changing scenario, where the same identity (ID) suffers from uncertain cloth changes. To learn cloth- and ID-invariant features, it is crucial to collect abundant training data with varying clothes, which is difficult in practice. To alleviate the reliance on rich data collection, we reinforce the feature learning process by designing powerful complementary data augmentation strategies, including positive and negative data augmentation. Specifically, the positive augmentation fulfills the ID space by randomly patching the person images with different clothes, simulating rich appearance to enhance the robustness against clothes variations. For negative augmentation, its basic idea is to randomly generate out-of-distribution synthetic samples by combining various appearance and posture factors from real samples. The designed strategies seamlessly reinforce the feature learning without additional information introduction. Extensive experiments conducted on both cloth-changing and -unchanging tasks demonstrate the superiority of our proposed method, consistently improving the accuracy over various baselines.

A novel star-shaped trinuclear platinum(II) complex based on a 1,3,5-triazine core displaying potent antiproliferative activity against TNBC by the mitochondrial injury and DNA damage mechanism

Polynuclear platinum(II) complexes represent a class of great prospective Pt-based antitumor drugs that may expand the antitumor spectrum and overcome the clinical problems of drug resistance and side effects of platinum-based drugs. Herein, a novel star-shaped trinuclear platinum(II) complex [Pt₃(L-3H)Cl₃] (1, L = 2,4,6-tris[(2-hydroxybenzyl)(2-pyridylmethyl)amine]-1,3,5-triazine) and its monomer [Pt(L'-H)Cl] (2, L' = (2-hydroxybenzyl)(2-pyridylmethyl)amine) were synthesized and characterized. The in vitro antiproliferative activities of complexes 1 and 2 against a panel of human cancer cell lines including MDA-MB-231 (triple-negative breast cancer, TNBC), MCF-7 (breast), HepG-2 (liver), and A549 (lung) were investigated. The results revealed that 1 exhibited much higher antiproliferative properties than its monomer 2 against the tested cell lines. Importantly, 1 possessed 3.3-fold higher antiproliferative activity as compared with cisplatin against the TNBC cell line MDA-MB-231. Another TNBC cell line MDA-MB-468 is also sensitive to 1. The results indicated that 1 might have the potential to act as a candidate for the treatment of TNBC. Cellular uptake and distribution studies showed that 1 could pass through the membrane of cells and enter into cells and mainly accumulate in the nuclei and mitochondria. 1 could bind to DNA in a cooperative groove-electrostatic-platinating binding mode and induce stronger DNA double-strand breaks (DSBs) and damaging effects on MDA-MB-231 than cisplatin (upregulation of γ-H2AX). Moreover, the DNA damage could not be easily repaired (upregulation of p53), which would exert a much positive influence on the overcoming of drug resistance. Additionally, flow cytometry studies showed that 1 arrested the cell cycle in the G0/G1 phase, induced mitochondrial membrane depolarization, increased ROS generation, and induced cell apoptosis. The results demonstrated that 1 could target simultaneously mitochondria and nuclei that gave rise to mitochondrial injury and DNA damage and ultimately efficiently promote the apoptotic death of tumor cells. Further mechanistic studies showed that 1 induced MDA-MB-231 cell apoptosis via the p53-mediated mitochondrial pathway by upregulating Bax and cytochrome c and downregulating Bcl-2 proteins, leading to the activation of caspase-3 and upregulation of the cleaved-PARP level. Taken together, 1 with such a synergic mechanism has great potential to be an effective anticancer agent that can overcome treatment resistance in TNBC.

Study of the doubly charmed tetraquark [Formula: see text]

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar [Formula: see text] tetraquark with a quark content of [Formula: see text] and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector [Formula: see text] state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the [Formula: see text] state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.

Angular Analysis of D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays and Search for CP Violation

The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9  fb^{-1}. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry.

Environmental BPDE induced human trophoblast cell apoptosis by up-regulating lnc-HZ01/p53 positive feedback loop

Human trophoblast cell apoptosis may induce miscarriage. Trophoblast cells are sensitive to environmental BaP-7,8-dihydrodiol-9,10-epoxide (BPDE). However, how BPDE induces human trophoblast cell apoptosis is still largely elusive. In this work, we used BPDE-treated human trophoblast cells and villous tissues collected from recurrent miscarriage and health control groups to explore the underlying mechanism of BPDE-induced human trophoblast cell apoptosis. Continued with our recent work, we found that lncRNA HZ01 (lnc-HZ01) could induce human trophoblast cell apoptosis. In mechanism, lnc-HZ01 up-regulated p53 expression level by suppressing its MDM2-mediated proteasomal degradation. Meanwhile, we found that p53 acted as lnc-HZ01 transcription factor and promoted lnc-HZ01 transcription. Thus, lnc-HZ01 and p53 composed a positive feedback loop in human trophoblast cells. In normal trophoblast cells, relatively low levels of lnc-HZ01 and p53 suppressed p53/caspase-3 apoptosis pathway, giving normal pregnancy. Upon BPDE exposure, BPDE up-regulated the expression levels of lnc-HZ01 and p53, triggered this positive feedback loop, activated the p53/caspase-3 apoptosis pathway, and then induced miscarriage. Collectively, we discovered new mechanism by which lnc-HZ01 regulated BPDE-induced human trophoblast cell apoptosis, providing scientific basis for the diagnosis and treatment of unexplained recurrent miscarriage.

Microbial Proline Racemase-Proline Dehydrogenase Cascade for Efficient Production of D-proline and N-boc-5-hydroxy-L-proline from L-proline

D-proline and N-boc-5-hydroxy-L-proline are key chiral intermediates in the production of eletriptan and saxagliptin, respectively. An efficient proline racemase-proline dehydrogenase cascade was developed for the enantioselective production of D-proline. It included the racemization of L-proline to DL-proline and the enantioselective dehydrogenation of L-proline in DL-proline. The racemization of L-proline to DL-proline used an engineered proline racemase (ProR). L-proline up to 1000 g/L could be racemized to DL-proline with 1 g/L of wet Escherichia coli cells expressing ProR within 48 h. The efficient dehydrogenation of L-proline in DL-proline was achieved using whole cells of proline dehydrogenase-producing Pseudomonas pseudoalcaligenes XW-40. Moreover, using a cell-recycling strategy, D-proline was obtained in 45.7% yield with an enantiomeric excess of 99.6%. N-boc-5-hydroxy-L-proline was also synthesized from L-glutamate semialdehyde, a dehydrogenated product of L-proline, in a 16.7% yield. The developed proline racemase-proline dehydrogenase cascade exhibits great potential and economic competitiveness for manufacturing D-proline and N-boc-5-hydroxy-L-proline from L-proline.

Tests of Lepton Universality Using B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} Decays

Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays are measured in intervals of the dilepton invariant mass squared. The measurements are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1} . The results are consistent with the standard model and previous tests of lepton universality in related decay modes. The first observation of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays is reported.

Observation of the Decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}

The first observation of the semileptonic b-baryon decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}, with a significance of 6.1σ, is reported using a data sample corresponding to 3  fb^{-1} of integrated luminosity, collected by the LHCb experiment at center-of-mass energies of 7 and 8 TeV at the LHC. The τ^{-} lepton is reconstructed in the hadronic decay to three charged pions. The ratio K=B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}) is measured to be 2.46±0.27±0.40, where the first uncertainty is statistical and the second systematic. The branching fraction B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})=(1.50±0.16±0.25±0.23)% is obtained, where the third uncertainty is from the external branching fraction of the normalization channel Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}. The ratio of semileptonic branching fractions R(Λ_{c}^{+})≡B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ}) is derived to be 0.242±0.026±0.040±0.059, where the external branching fraction uncertainty from the channel Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ} contributes to the last term. This result is in agreement with the standard model prediction.

[Analysis of clinical phenotype and genotype of Chinese children with disorders of sex development]

Objective: To explore the heterogeneity and correlation of clinical phenotypes and genotypes in children with disorders of sex development (DSD). Methods: A retrospective study of 1 235 patients with clinically proposed DSD in 36 pediatric medical institutions across the country from January 2017 to May 2021. After capturing 277 DSD-related candidate genes, second-generation sequencing was performed to analyzed the heterogeneity and correlation combined with clinical phenotypes. Results: Among 1 235 children with clinically proposed DSD, 980 were males and 255 were females of social gender at the time of initial diagnosis with the age ranged from 1 day of age to 17.92 years. A total of 443 children with pathogenic variants were detected through molecular genetic studies, with a positive detection rate of 35.9%. The most common clinical phenotypes were micropenis (455 cases), hypospadias (321 cases), and cryptorchidism (172 cases) and common mutations detected were in SRD5A2 gene (80 cases), AR gene (53 cases) and CYP21A2 gene (44 cases). Among them, the SRD5A2 mutation is the most common in children with simple micropenis and simple hypospadias, while the AMH mutation is the most common in children with simple cryptorchidism. Conclusions: The SRD5A2 mutation is the most common genetic variant in Chinese children with DSD, and micropenis, cryptorchidism, and hypospadias are the most common clinical phenotypes. Molecular diagnosis can provide clues about the biological basis of DSD, and can also guide clinicians to perform specific clinical examinations. Target sequence capture probes and next-generation sequencing technology can provide effective and economical genetic diagnosis for children with DSD.