A homozygous frameshift variant in SYCP2 caused meiotic arrest and non-obstructive azoospermia.

Genetic causation for the majority of non-obstructive azoospermia (NOA) remains unclear. Mutations in synaptonemal complex (SC)-associated genes could cause meiotic arrest and NOA. Previous studies showed that heterozygous truncating variants in SYCP2 encoding a protein essential for SC formation, are associated with non-obstructive azoospermia and severe oligozoospermia. Herein, we showed a homozygous loss-of-function variant in SYCP2 (c.2689_2690insT) in an NOA-affected patient. And this variant was inherited from heterozygous parental carriers by natural reproduction. HE, IF, and meiotic chromosomal spread analyses demonstrated that spermatogenesis was arrested at the zygotene stage in the proband with NOA. Thus, this study revealed that SYCP2 associated with NOA segregates in an autosomal recessive inheritance pattern, rather than an autosomal dominant pattern. Furthermore, our study expanded the knowledge of variants in SYCP2 and provided new insight into understanding the genetic etiology of NOA.

Nanoscale phase separation on an AlGaN surface characterized by scanning diffusion microscopy.

AlGaN is an important material for deep ultraviolet optoelectronic devices and electronic devices. The phase separation on the AlGaN surface means small-scale compositional fluctuations of Al, which is prone to degrade the performance of devices. In order to study the mechanism of the surface phase separation, the Al0.3Ga0.7N wafer was investigated by the scanning diffusion microscopy method based on the photo-assisted Kelvin force probe microscope. The response of the surface photovoltage near the bandgap was quite different for the edge and the center of the island on the AlGaN surface. We utilize the theoretical model of scanning diffusion microscopy to fit the local absorption coefficients from the measured surface photovoltage spectrum. During the fitting process, we introduce as and ab parameters (bandgap shift and broadening) to describe the local variation of absorption coefficients α(as, ab, λ). The local bandgap and Al composition can be calculated quantitatively from the absorption coefficients. The results show that there is lower bandgap (about 305 nm) and lower Al composition (about 0.31) at the edge of the island, compared with those at the center of the island (about 300 nm for bandgap and 0.34 for Al composition). Similar to the edge of the island, there is a lower bandgap at the V-pit defect which is about 306 nm corresponding to the Al composition of about 0.30. These results mean Ga enrichment both at the edge of the island and the V-pit defect position. It proves that scanning diffusion microscopy is an effective method to review the micro-mechanism of AlGaN phase separation.

Chiral template-induced porphyrin-based self-assembled materials for electrochemical chiral sensing.

Chirality plays a key role in many fields of natural sciences as well as life sciences. Chiral materials are widely developed and used for electrochemical chiral recognition. In recent years, carbon quantum dots (CQDs) have been widely used as a novel carbon nanomaterial due to their excellent charge transfer properties, good biocompatibility, and low cost. The special structure of π-conjugated porphyrin attracts attention. Supramolecular self-assembly shows a way to construct chiral materials by self-assembling simple molecules into chiral composites. Herein, we demonstrate the self-assembly of achiral porphyrins induced by chiral carbon quantum dots assembled from L- and or D-tryptophan (L- and or D-Trp) with carbon quantum dots, resulting in 5,10,15,20-tetrakis (4-carboxyPheyl) (TCPP) self-assembled structure. The electrochemical chiral recognition of chiral self-assembled materials was studied using Phenylalanine (Phe) enantiomer as a chiral analyte. Electrochemical chiral recognition results showed that the chiral self-assembled materials induced by chiral templates have a good ability to discriminate Phe enantiomers. Therefore, this research provides a new idea for the synthesis of chiral composites and further expands applications to electrochemical chiral recognition.

Semiconductor-Metal Phase Transition and Emergent Charge Density Waves in 1T-ZrX2 (X = Se, Te) at the Two-Dimensional Limit.

A charge density wave (CDW) is a collective quantum phenomenon in metals and features a wavelike modulation of the conduction electron density. A microscopic understanding and experimental control of this many-body electronic state in atomically thin materials remain hot topics in materials physics. By means of material engineering, we realized a dimensionality and Zr intercalation induced semiconductor-metal phase transition in 1T-ZrX2 (X = Se, Te) ultrathin films, accompanied by a commensurate 2 × 2 CDW order. Furthermore, we observed a CDW energy gap of up to 22 meV around the Fermi level. Fourier-transformed scanning tunneling microscopy and angle-resolved photoemission spectroscopy reveal that 1T-ZrX2 films exhibit the simplest Fermi surface among the known CDW materials in TMDCs, consisting only of a Zr 4d derived elliptical electron conduction band at the corners of the Brillouin zone.

[Droplet freeze-thawing system based on solid surface vitrification and laser rewarming].

Ultra-rapid cooling and rewarming rate is a critical technical approach to achieve ice-free cells during the freezing and melting process. A set of ultra-rapid solid surface freeze-thaw visualization system was developed based on a sapphire flim, and experiments on droplet freeze-thaw were carried out under different cryoprotectant components, volumes and laser energies. The results showed that the cooling rate of 1 µL mixed cryoprotectant [1.5 mol/L propylene glycol (PG) + 1.5 mol/L ethylene glycol (EG) + 0.5 mol/L trehalose (TRE)] could be 9.2×10 3 °C/min. The volume range of 1-8 µL droplets could be vitrified. After comparing the proportions of multiple cryoprotectants, the combination of equal proportion mixed permeability protectant and trehalose had the best vitrification freezing effect and more uniform crystallization characteristics. During the rewarming operation, the heating curve of glassy droplets containing gold nanoparticles was measured for the first time under the action of 400-1 200 W laser power, and the rewarming rate was up to the order of 10 6 °C/min. According to the droplet images of different power rewarming processes, the laser power range for ice-free rewarming with micron-level resolution was clarified to be 1 400-1 600 W. The work of this paper simultaneously realizes the ultra-high-speed temperature ramp-up, transient visual observation and temperature measurement of droplets, providing technical means for judging the ice free droplets during the freeze-thaw process. It is conducive to promoting the development of ultra-rapid freeze-thaw technology for biological cells and tissues.

Novel bi-allelic MSH4 variants causes meiotic arrest and non-obstructive azoospermia.

BACKGROUND: Non-obstructive azoospermia (NOA) is one of the most severe type in male infertility, and the genetic causes of NOA with meiotic arrest remain elusive. METHODS: Four Chinese families with NOA participated in the study. We performed whole-exome sequencing (WES) for the four NOA-affected patients in four pedigrees. The candidate causative gene was further verified by Sanger sequencing. Hematoxylin and eosin staining (H&E) and immunohistochemistry (IHC) were carried out to evaluate the stage of spermatogenesis arrested in the patients with NOA. RESULTS: We identified two novel homozygous frameshift mutations of MSH4 and two novel compound heterozygous variants in MSH4 in four pedigrees with NOA. Homozygous loss of function (LoF) variants in MSH4 was identified in the NOA-affected patient (P9359) in a consanguineous Chinese family (NM_002440.4: c.805_812del: p.V269Qfs*15) and one patient with NOA (P21504) in another Chinese family (NM_002440.4: c.2220_2223del:p.K741Rfs*2). Also, compound heterozygous variants in MSH4 were identified in two NOA-affected siblings (P9517 and P9517B) (NM_002440.4: c.G1950A: p.W650X and c.2179delG: p.D727Mfs*11), and the patient with NOA (P9540) (NM_002440.4: c.G244A: p.G82S and c.670delT: p.L224Cfs*3). Histological analysis demonstrated lack of spermatozoa in seminiferous tubules of all patients and IHC showed the spermatogenesis arrested at the meiotic prophase I stage. Consistent with the autosomal recessive mode of inheritance, all of these mutations were inherited from heterozygous parental carriers. CONCLUSIONS: We identified that six novel mutations in MSH4 responsible for meiotic arrest and NOA. And these results provide researchers with a new insight to understand the genetic etiology of NOA and to identify new loci for genetic counselling of NOA.

Proteomic profiling of kidney samples in patients with pure membranous and proliferative lupus nephritis.

Renal injury in lupus nephritis (LN) does not manifest as one uniform entity. The clinical presentation, management, and prognosis of membranous LN (MLN) differ from that of the proliferative LN (PLN). Differentiating the molecular mechanisms involved in MLN and PLN and discovering the reliable biomarkers for early diagnosis and target therapy are important. We compared the kidney protein expression patterns of 11 pure MLN and 12 pure PLN patients on formalin-fixed paraffin-embedded (FFPE) kidney tissues using label-free liquid chromatography-mass spectrometry (LC-MS) for quantitative proteomics analysis. FunRich software was used to identify proteins in differentially expressed pathways. Quantitative comparisons of differentially expressed proteins in each patient were further analyzed based on protein intensity levels determined by LC-MS. The protein-protein interaction (PPI) network of the differentially expressed genes (DEGs) was established through Search Tool for the Retrieval of Interacting Genes database (STRING) website, visualized by Cytoscape. A total of 5112 proteins were identified. In total, 12 significantly upregulated (fold change ≥2, p < 0.05) proteins were identified in the MLN group and 220 proteins (fold change ≥2, p < 0.05) were upregulated in the PLN group. Further analysis showed that the most significant upregulated pathway involved in MLN was histone deacetylase (HDAC) class I pathway, and the three most significant upregulated pathways in PLN were interferon signaling, interferon gamma signaling, and the immune system. Next, we selected sirtuin-2 (SIRT2) in MLN, and vascular cell adhesion protein 1 (VCAM1) and Bcl-xl in PLN for further mass spectrometry (MS) intensity and PPI analysis. SIRT2 expression was significantly increased in the MLN group compared with the PLN group, and VCAM1, Bcl-xl expression was significantly increased in the PLN group compared with the MLN group, based on MS intensity. These results may help to improve our understanding of the underlying molecular mechanisms of MLN and PLN and provide potential targets for the diagnosis and treatment of different subclasses of LN.

Study on cryopreservation of mouse single seminiferous tubule.

Cryopreservation of single seminiferous tubule is significant for fertility preservation, especially for male patients with cryptorchidism, Y-chromosome deletion and orchitis. However, there are few studies on cryopreservation of single seminiferous tubule. This study proposes several improved strategies for cryopreservation of single seminiferous tubule in mice. First, single seminiferous tubule was cryopreserved with modified slow freezing and vitrification methods. The results showed that the apoptosis negative rates of spermatogenic cells in single seminiferous tubule with modified slow freezing method were significantly higher than vitrification with plastic slide. Then, plastic slide and two metal vitrification carriers with high thermal conductivity, copper mesh and aluminum foil, were used to vitrify single seminiferous tubule. The metal carriers could improve the outcome of vitrification than plastic slide. The apoptosis negative rates of spermatogenic cells in the aluminum foil group was significantly higher than that in the copper mesh group. Finally, single seminiferous tubule was perfused with CPAs by micro-injection technique and vitrified. The results of cryo-microscopy experiments showed that the ice crystals formed inside the injected seminiferous tubule was reduced during the cooling process, the apoptosis negative rate of spermatocytes, spermatids and Sertoli cells were significantly higher than that of the non-injection group, indicating that the injection technique can effectively improve the effect of vitrification. This study has potential clinical value for in-vitro culture of spermatogonial stem cells and autologous testicular tissue grafting in patients with azoospermia.

Low-Intensity Pulsed Ultrasound Alleviates Human Testicular Leydig Cell Senescence In Vitro.

Aging has a significant negative impact on human testicular function; steroidogenesis is gradually impaired, and testosterone replacement therapy still has many risks. Low-intensity pulsed ultrasound (LIPUS) has been used as a novel non-invasive treatment for male erectile dysfunction and other fields, and has been shown to increase testosterone levels in animal models. Testosterone is synthesized and secreted by Leydig cells (LCs), and the serum testosterone level decreases after aging due to the LCs senescence. However, the effect of LIPUS on human senescent LCs has not been reported. In this study, human senescent LCs were isolated and stimulated with different energy intensities in vitro, and cell morphology, cell apoptosis, cell proliferation, cell senescence levels, lipid droplet number, testosterone and INSL3 secretion levels were tested and analyzed. Quantitative Polymerase Chain Reaction (QPCR) and Western Blot were performed to compare cell senescence characteristics and the expression profile of key pathways of testosterone secretion, and transcriptome analysis was performed to explore the signaling pathways of LCs alteration after LIPUS stimulation. It was safe and effective to stimulate LCs with the 75 mW/cm2 energy of LIPUS in vitro, which not only improved the senescence phenotype, but also effectively enhanced the secretory function of LCs in vitro, and increased the expression of key pathways of the testosterone synthesis pathway. These results suggest that LIPUS could be used as a novel treatment to human senescent LCs with decreased testosterone secretion levels in vitro.

[Establishment of a system for regulating the gene expression of embryonic mouse cerebral cortex neural stem cells by in utero electroporation]. / å­å®«å† ç”µç©¿å­”æ³•è°ƒæŽ§é¼ èƒšå¤§è„‘çš®è´¨ç¥žç»å¹²ç»†èƒžåŸºå› è¡¨è¾¾ä½“ç³»çš„å»ºç«‹.

OBJECTIVES: To establish a system for regulating the gene expression of embryonic mouse cerebral cortex neural stem cells (NSCs) using in utero electroporation (IUE). METHODS: At embryonic day 14.5, the mouse cerebral cortex NSCs were electro-transfected with the pCIG plasmid injected into the ventricle of the mouse embryo. At embryonic day 16.5 or day 17.5, embryonic mouse brain tissues were collected to prepare frozen sections. Immunofluorescence staining was used to observe the proliferation, apoptosis, division, directional differentiation, migration, and maturation of NSCs. RESULTS: The differentiation of NSCs into intermediate progenitors, the proliferation and apoptosis of NSCs, and the morphological development of radial axis of radial glial cells were observed at embryonic day 16.5. The differentiation of NSCs into neurons in layers V-VI of the cerebral cortex, the migration of NSCs to the lateral cerebral cortex, the development of dendrites of migrating neurons, and the maturation of neurons were observed at embryonic day 17.5. CONCLUSIONS: The system for regulating the gene expression of embryonic mouse cerebral cortex NSCs can be established using IUE, which is useful for the study of neural development related to the proliferation, apoptosis, division, directional differentiation, migration and maturation of NSCs in the cerebral cortex.

Clinical treatment outcomes and their changes in extremely preterm twins: a multicenter retrospective study in Guangdong Province, China. / è¶ æœªæˆç†ŸåŒèƒŽå„¿ä¸´åºŠæ•‘æ²»ç»“å±€åŠå˜åŒ–åˆ†æžï¼šä¸€é¡¹å¹¿ä¸œçœå¤šä¸­å¿ƒå›žé¡¾æ€§ç ”ç©¶.

OBJECTIVES: To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China. METHODS: A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups. RESULTS: Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05). CONCLUSIONS: There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.

von Willebrand factor variants in C3 glomerulopathy: A Chinese cohort study.

C3 glomerulopathy (C3G) is a rare renal disease characterized by predominant glomerular C3 staining. Complement alternative pathway dysregulation due to inherited complement defects is associated with C3G. To identify novel C3G-related genes, we screened 86 genes in the complement, coagulation and endothelial systems in 35 C3G patients by targeted genomic enrichment and massively parallel sequencing. Surprisingly, the most frequently mutated gene was VWF. Patients with VWF variants had significantly higher proteinuria levels, higher crescent formation and lower factor H (FH) levels. We further selected two VWF variants to transiently express the von Willebrand factor (vWF) protein, we found that vWF expression from the c.1519A > G variant was significantly reduced. In vitro results further indicated that vWF could regulate complement activation, as it could bind to FH and C3b, act as a cofactor for factor I-mediated cleavage of C3b. Thus, we speculated that vWF might be involved in the pathogenesis of C3G.

Increased anxiety was found in serpini1 knockout zebrafish larval.

Serpini1, which encodes neuroserpin, has been implicated in the development and normal function of the nervous system. Mutations in serpini1 cause familial encephalopathy, a rare neurodegenerative disorder characterized with neuroserpin inclusion bodies. However, function of neuroserpin in the nervous system is not fully understood. In this study, we generated a novel serpini1 mutant zebrafish model to investigate the loss of function of neuroserpin. Serpini1- deficient mutation was created with the CRISPR/Cas9 technique. No severe morphological characteristics were found in serpini1- deficient zebrafish. Serpini1-/- zebrafish larvae did not cause locomotor defects but displayed anxiety-like behavior. Extension of motoneurons axon defect was observed in serpini1-/- zebrafish. Furthermore, RNA-sequencing analysis revealed that loss of serpini1 resulted in affected expression of neurodegeneration-related genes.

Vitrification with microinjection of single seminiferous tubules: an efficient cryopreservation approach for limited testicular tissue.

RESEARCH QUESTION: Is vitrification with microinjection of single seminiferous tubules an efficient cryopreservation approach for limited testicular tissue? DESIGN: Testicular tissue from 10 patients with normal spermatogenesis were assigned to a fresh control group or one of the following cryopreservation procedures: uncontrolled slow freezing (USF) using either 1.5 or 2.1 M DMSO combined with sucrose and vitrification with or without single seminiferous tubules microinjection. RESULTS: Single seminiferous tubules microinjected with cryoprotective agents (CPA) enhanced the penetration of CPA compared with CPA-treated testicular tissue fragments. Microinjection of seminiferous tubules (VLP) maintained tubule structural integrity and germ cell numbers, and reduced spermatogonial apoptosis after cryopreservation compared with vitrification without microinjection (apoptosis rate: VLP versus vitrification without microinjection, P = 0.047; VLP versus USF, P= 0.049). Freezing of single seminiferous tubules using 0.25-ml straws and traditional sperm freezing methods protected sperm retrieval and recovery rates, and the progressive motility index. CONCLUSIONS: Vitrification of single seminiferous tubule with microinjection of low CPA concentration is an effective approach to testicular cryopreservation.

[Progress in research and development of Xanthoceras sorbifolia].

Xanthoceras sorbifolia, an excellent oil-rich woody species, has high comprehensive economic value in edible, medicinal, and ornamental fields. The chemical composition, pharmacological effect, and quality control of X. sorbifolia were introduced, and its development and application were reviewed in this study. As revealed by the previous research, the main chemical constituents of X. sorbifolia were triterpenoids, flavonoids, fatty acids, phenylpropanoids, steroids, phenolic acids, organic acids, etc. It possesses pharmacological effects, such as neuroprotection, bacteriostasis, anti-oxidation, anti-tumor, anti-inflammation, analgesia, anti-HIV, and anti-coagulation. X. sorbifolia is widely applied in medical, food, chemical industry, and other fields, and deserves in-depth research and development.

The posttranslational modification of HDAC4 in cell biology: Mechanisms and potential targets.

Histone deacetylase 4 (HDAC4) is a member of the HDACs family, its expression is closely related to the cell development. The cell is an independent living entity that undergoes proliferation, differentiation, senescence, apoptosis, and pathology, and each process has a strict and complex regulatory system. With deepening of its research, the expression of HDAC4 is critical in the life process. This review focuses on the posttranslational modification of HDAC4 in cell biology, providing an important target for future disease treatment.

Direct Observation of Full-Gap Superconductivity and Pseudogap in Two-Dimensional Fullerides.

Alkali-fulleride superconductors with a maximum critical temperature T_{c}∼40 K exhibit a similar electronic phase diagram to that of unconventional high-T_{c} superconductors. Here we employ cryogenic scanning tunneling microscopy to show that trilayer K_{3}C_{60} displays fully gapped strong coupling s-wave superconductivity, accompanied by a pseudogap above T_{c}∼22 K and within vortices. A precise control of the electronic correlations and potassium doping enables us to reveal that superconductivity occurs near a superconductor-Mott-insulator transition and reaches maximum at half-filling. The s-wave symmetry retains over the entire phase diagram, which, in conjunction with an abrupt decline of the superconductivity below half-filling, indicates that alkali fullerides are predominantly phonon-mediated superconductors, although the electronic correlations also come into play.

Three-Dimensional Cuprous Lead Bromide Framework with Highly Efficient and Stable Blue Photoluminescence Emission.

Considering the instability and low photoluminescence quantum yield (PLQY) of blue-emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4 )2 ]CuPbBr5 with new type of three-dimensional (3D) anionic framework. [(NH4 )2 ]CuPbBr5 exhibits strong band-edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4 )2 ]CuPbBr5 also displays broadband red light emissions derived from self-trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non-perovskite bimetallic halide with highly efficient and stable blue light emission.

Case report of a 28-year-old man with aortic dissection and pulmonary shadow due to granulomatosis with polyangiitis.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is characterised by the main violation of the upper and lower respiratory tract and kidney. GPA is considered a systemic vasculitis of medium-sized and small blood vessels where aortic involvement is extremely rare. CASE PRESENTATION: A 28-year-old male was admitted to the hospital due to 4 h of chest pain. Computed tomography scan of the aorta showed a thickened aortic wall, pulmonary lesions, bilateral pleural effusion and pericardial effusion. The aortic dissection should be considered. An emergency operation was performed on the patient. Surgical biopsies obtained from the aortic wall showed destructive changes, visible necrosis, granulation tissue hyperplasia and a large number of acute and chronic inflammatory cells. Nearly a year later, the patient was re-examined for significant pulmonary lesions. His laboratory studies were significantly positive for anti-neutrophilic antibody directed against proteinase 3. Finally, the diagnosis of GPA was obviously established. CONCLUSIONS: Although GPA rarely involves the aorta, we did not ignore the fact that GPA may involve large blood vessels. In addition, GPA should be included in the systemic vasculitis that can give rise to aortitis and even aortic dissection.