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A bis(pyridyl)amine-bipyridine-iron(II) framework (Fe(BPAbipy)) of complexes 1-3 is reported to shed light on the multistep nature of CO2 reduction. Herein, photocatalytic conversion of CO2 to CO even at low CO2 concentration (1 %), together with detailed mechanistic study and DFT calculations, reveal that 1 first undergoes two sequential one-electron transfer affording an intermediate with electron density on both Fe and ligand for CO2 binding over proton. The following 2 H+ -assisted Fe-CO formation is rate-determining for selective CO2 -to-CO reduction. A pendant, proton-shuttling α-OH group (2) initiates PCET for predominant H2 evolution, while an α-OMe group (3) cancels the selectivity control for either CO or H2 . The near-unity selectivity of 1 and 2 enables self-sorting syngas production at flexible CO/H2 ratios. The unprecedented results from one kind of molecular catalyst skeleton encourage insight into the beauty of advanced multi-electron and multi-proton transfer processes for robust CO2 RR by photocatalysis.

Hydride transfer is a critical elementary reaction step that spans biological catalysis, organic synthesis, and energy conversion. Conventionally, hydride transfer reactions are carried out using (bio)molecular hydride reagents under homogeneous conditions. Herein, we report a conceptually distinct heterogeneous hydride transfer reaction via the net electrocatalytic hydrogen reduction reaction (HRR) which reduces H2 to hydrides. The reaction proceeds by H2 dissociative adsorption on a metal electrode to form surface M−H species, which are then negatively polarized to drive hydride transfer to molecular hydride acceptors with up to 95% Faradaic efficiency. We find that the hydride transfer reactivity of surface M−H species is highly tunable and its thermochemistry depends on the applied potential in a Nernstian fashion. Thus, depending on the electrode potential, we observe that the thermodynamic hydricity of Pt−H on the same Pt electrode can continuously span a range of >40 kcal mol−1. This work highlights the critical role of electrical polarization on heterogeneous hydride transfer reactivity and establishes a sustainable strategy for accessing reactive hydrides directly from H2.

BACKGROUND: Beclin-1 is an autophagy gene and higher levels suggest mammalian testicular damage. Our study aims at exploring the role of Beclin-1 in non-obstructive azoospermia (NOA) patients and clarifying the predictive value of Beclin-1for sperm retrieval in microdissection testicular sperm extraction (micro-TESE). METHODS: In the present study, 62 NOA patients were finally recruited. Serum hormone including luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol II (E2), testosterone (T) and prolactin (PRL), as well as testicular volume were measured. Testicular histopathology was diagnosed by two independent pathologists. The expression of Beclin-1 was detected by real-time PCR in testicular tissue. RESULTS: Our study illustrated that Beclin-1 was differently expressed in three pathological types of NOA. Compared with hypospermatogenesis (HS, P=0.002) or maturation arrest (MA, P=0.049), Beclin-1 showed significantly up-regulated in Sertoli cell-only syndrome (SCOS) group. Moreover, Beclin-1 expression was obviously positive related with serum LH (rho =0.269, P=0.036), meanwhile significantly negative correlation with testicular volume (rho =−0.370, P=0.003), serum T (rho =−0.326, P=0.010), Johnsen score (rho =−0.318, P=0.012), and pathologic type (rho =−0.452, P

ImportanceThe potential effects of long-term occupational exposure to formaldehyde (FA) on human semen quality is not clear.ObjectiveTo assess whether long-term occupational exposure to FA is associated with semen quality.Design, Setting, and ParticipantsThis population-based cohort study was conducted from June 1 to June 30, 2021, in Xi’an, China. Participants were adults aged 23 to 40 years who had lived in the study area for 24 months or longer. Data analysis was performed from September 1 to October 1, 2021.ExposuresLong-term occupational exposure to FA was measured using a formaldehyde detector, and the FA exposure index (FEI) was calculated as follows: FEI = final concentration of FA (mg/m3) × work time during a workday (hour) × cumulative workdays (year).Main Outcomes and MeasuresSemen samples were collected by masturbation after 3 to 7 days of abstinence and were then assessed by the computer-automated semen analysis system, Baso-Papanicolaou staining, and sperm-chromatin structure assay.ResultsA total of 205 men (mean [SD] age, 29.49 [3.64] years), with 124 individuals in the FA exposure group (mean [SD] FEI, 73.72 [54.86]) and 81 age-matched controls, were included in the final analysis. Long-term personal occupational exposure to FA was significantly associated with poor semen quality. Specifically, a 1-unit increase in FEI was associated with a change of −0.99% (95% CI, −1.00% to −0.98%) in total sperm motility, −0.99% (95% CI, −0.99% to −0.97%) in progressive sperm motility, −0.05% (95% CI, −0.08% to −0.02%) in curvilinear velocity, −0.07% (95% CI, −0.10% to −0.04%) in straight line velocity, −0.07% (95% CI, −0.10% to −0.04%) in time-average velocity, −0.98% (95% CI, −0.99% to −0.93%) in normal sperm morphology, −0.24% (95% CI, −0.35% to −0.11%) in seminal neutral glucosidase, −0.61% (95% CI, −0.66% to −0.56%) in seminal plasma zinc, 0.52% (95% CI, 0.15% to 1.02%) in beat cross frequency, and 0.10% (95% CI, 0.06% to 0.14%) in the DNA fragmentation index. These associations remained significant after adjusting for confounding factors. Furthermore, subgroup analysis found that high levels of oxidative stress might promote the associations between FA exposure and semen quality.Conclusions and RelevanceThis study found an association between long-term occupational exposure to FA and semen quality. This deterioration was dose and time dependent and might be induced by oxidative stress.

This account summarizes our recent work on metal-quinoid carbene (QC) chemistry including (a) dirhodium-catalyzed QC C(sp2)–H insertion reactions enabled by a C-centered carbene-transfer reactivity, (b) the isolation, characterization, and dual reactivity of Ru(II) porphyrin QC complexes, and (c) iridium(III) porphyrin-catalyzed QC C(sp3)–H insertion reaction initiated by an O-centered hydrogen-atom transfer reactivity of metal–QC species.1 Introduction2 Catalytic Quinoid Carbene Insertions into C(sp2)–H Bonds Enabled by Carbene-Transfer Reactivity3 Ruthenium(II) Porphyrin Quinoid Carbene Complexes and Dual Reactivity4 Catalytic Quinoid Carbene Insertions into C(sp3)–H Bonds Enabled by Hydrogen-Atom-Transfer Reactivity5 Perspective and Outlook

Described herein is an IrIII /porphyrin-catalyzed intermolecular C(sp3 )-H insertion reaction of a quinoid carbene (QC). The reaction was designed by harnessing the hydrogen-atom transfer (HAT) reactivity of a metal-QC species with aliphatic substrates followed by a radical rebound process to afford C-H arylation products. This methodology is efficient for the arylation of activated hydrocarbons such as 1,4-cyclohexadienes (down to 40 min reaction time, up to 99 % yield, up to 1.0 g scale). It features unique regioselectivity, which is mainly governed by steric effects, as the insertion into primary C-H bonds is favored over secondary and/or tertiary C-H bonds in the substituted cyclohexene substrates. Mechanistic studies revealed a radical mechanism for the reaction.

We report the isolation, X-ray crystal structures, reactivity and DFT calculations of iron- and ruthenium-mono(dialkylcarbene) and osmium-bis(dialkylcarbene) porphyrins and diarylcarbene transfer/insertion reactions catalyzed by iron-mono(dialkylcarbene) porphyrin., Alkyl-substituted carbene (CHR or CR2, R = alkyl) complexes have been extensively studied for alkylcarbene (CHR) ligands coordinated with high-valent early transition metal ions (a.k.a. Schrock carbenes or alkylidenes), yet dialkylcarbene (CR2) complexes remain less developed with bis(dialkylcarbene) species being little (if at all) explored. Herein, several group 8 metal porphyrin dialkylcarbene complexes, including Fe- and Ru-mono(dialkylcarbene) complexes [M(Por)(Ad)] (1a,b, M = Fe, Por = porphyrinato dianion, Ad = 2-adamantylidene; 2a,b, M = Ru) and Os-bis(dialkylcarbene) complexes [Os(Por)(Ad)2] (3a–c), are synthesized and crystallographically characterized. Detailed investigations into their electronic structures reveal that these complexes are formally low-valent M(ii)-carbene in nature. These complexes display remarkable thermal stability and chemical inertness, which are rationalized by a synergistic effect of strong metal-carbene covalency, hyperconjugation, and a rigid diamondoid carbene skeleton. Various spectroscopic techniques and DFT calculations suggest that the dialkylcarbene Ad ligand is unique compared to other common carbene ligands as it acts as both a potent σ-donor and π-acceptor; its unique electronic and structural features, together with the steric effect of the porphyrin macrocycle, make its Fe porphyrin complex 1a an active and robust catalyst for intermolecular diarylcarbene transfer reactions including cyclopropanation (up to 90% yield) and X–H (X = S, N, O, C) insertion (up to 99% yield) reactions.

Direct C-H bond functionalization catalyzed by non-precious transition metals is an attractive strategy in synthetic chemistry. Compared with the precious metals rhodium, palladium, ruthenium, and iridium commonly used in this field, catalysis based on non-precious metals, especially the earth-abundant ones, is appealing due to the increasing demand for environmentally benign and sustainable chemical processes. Herein, developments in iron- and cobalt-catalyzed C(sp3)-H bond functionalization reactions are described, with an emphasis on their applications in organic synthesis, i.e., the synthesis of natural products and pharmaceuticals and/or their modification.

Visible light driven nitrene transfer and insertion reactions of organic azides are an attractive strategy for the design of C–N bond formation reactions under mild reaction conditions, the challenge being lack of selectivity as a free nitrene reactive intermediate is usually involved. Herein is described an iron(iii) porphyrin catalysed sp3 C–H amination and alkene aziridination with selectivity by using organic azides as the nitrogen source under blue LED light (469 nm) irradiation. The photochemical reactions display chemo- and regio-selectivity and are effective for the late-stage functionalization of natural and bioactive compounds with complexity. Mechanistic studies revealed that iron porphyrin plays a dual role as a photosensitizer and as a catalyst giving rise to a reactive iron–nitrene intermediate for subsequent C–N bond formation., An iron(iii) porphyrin catalysed sp3 C–H amination and alkene aziridination with broad substrate scope under mild conditions is conducted, with selectivity through the use of organic azides as the nitrogen source under blue LED light irradiation.

The factors associated with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis relapse are yet to be elucidated.To investigate the factors associated with relapse and prognosis of anti-NMDA receptor encephalitis.This retrospective study included patients diagnosed with anti-NMDA receptor encephalitis admitted to the First Affiliated Hospital of Zhengzhou University from January 2013 to October 2019. The clinical features, auxiliary examinations, treatment regimens, and follow-up were recorded. The outcomes were relapse and 2-year disease prognosis.A total of 160 patients were included. Consequently, 6 (5%) deaths, 34 (25.4%) relapses, and 19 (15.2%) patients had a poor prognosis (modified Rankin score (mRS) ≥3) were recorded. The multivariable analyses showed that age (p = .011), abnormal magnetic resonance imaging (MRI) (p = .019), glucocorticoid pulse (p = .009), and intracranial pressure (p = .023) were independently associated with the relapse, while age (p = .030) and central hypoventilation (p = .020) were independently associated with a poor prognosis at 2 years.Glucocorticoid pulse therapy reduces the relapse of anti-NMDA receptor encephalitis. Age, abnormal MRI, and intracranial pressure are risk factors for relapse, while age and central hypoventilation are independently associated with poor prognosis.

Vascular invasion (VI) in hepatocellular carcinoma (HCC) is an important clinical parameter to predict survival. In this study, we collected microRNA (miRNA) expression data from HCC patients using The Cancer Genome Atlas database and identified a novel miRNA signature associated with VI. First, we categorized HCC patients into groups with or without VI (VI+ and VI-). We identified three miRNAs (miRNA-210, miRNA-10b, and miRNA-9-1) that were associated with VI according to a Kaplan-Meier analysis. This three-miRNA signature exhibited good predictive ability for VI in patients with HCC according to a receiver operating characteristic curve analysis at 1, 3, and 5 years. Patients with HCC with a high risk score exhibited a trend toward worse outcomes as determined by multivariable Cox regression and stratified analyses. This three-miRNA signature provides an accurate prediction of VI and can be used as an independent prognostic indicator for predicting VI in HCC patients.

High-valent iron-nitrido species are nitrogen analogues of iron-oxo species which are versatile reagents for C-H oxidation. Nonetheless, C-H activation by iron-nitrido species has been scarcely explored, as this is often hampered by their instability and short lifetime in solutions. Herein, the hydrogen atom transfer (HAT) reactivity of an Fe porphyrin nitrido species (2 c) toward C-H substrates was studied in solutions at room temperature, which was achieved by nanosecond laser flash photolysis (LFP) of its FeIII -azido precursor (1 c) supported by a bulky bis-pocket porphyrin ligand. C-H bonds with bond dissociation enthalpies (BDEs) of up to ≈84 kcal mol-1 could be activated, and the second-order rate constants (k2 ) are on the order of 102 -104 s-1 m-1 . The Fe-amido product formed after HAT could further release ammonia upon protonation.

Reliable methods for enantioselective cis-dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis-α-[FeII (2-Me2 -BQPN)(OTf)2 ], which bears a tetradentate N4 ligand (Me2 -BQPN=(R,R)-N,N'-dimethyl-N,N'-bis(2-methylquinolin-8-yl)-1,2-diphenylethane-1,2-diamine), was prepared and characterized. With this complex as the catalyst, a broad range of trisubstituted electron-deficient alkenes were efficiently oxidized to chiral cis-diols in yields of up to 98 % and up to 99.9 % ee when using hydrogen peroxide (H2 O2 ) as oxidant under mild conditions. Experimental studies (including 18 O-labeling, ESI-MS, NMR, EPR, and UV/Vis analyses) and DFT calculations were performed to gain mechanistic insight, which suggested possible involvement of a chiral cis-FeV (O)2 reaction intermediate as an active oxidant. This cis-[FeII (chiral N4 ligand)]2+ /H2 O2 method could be a viable green alternative/complement to the existing OsO4 -based methods for asymmetric alkene dihydroxylation reactions.

Direct C-H bond functionalization catalyzed by non-precious transition metals is an attractive strategy in synthetic chemistry. Compared with the precious metals rhodium, palladium, ruthenium, and iridium commonly used in this field, catalysis based on non-precious metals, especially the earth-abundant ones, is appealing due to the increasing demand for environmentally benign and sustainable chemical processes. Herein, developments in iron- and cobalt-catalyzed C(sp

Supplemental Digital Content is available in the text, Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease, and its mortality rate is 10% to 20%. However, there are currently only a few markers to predict the prognosis in patients with TTP. We aimed to identify several clinical indices and laboratory parameters for predicting the prognosis of TTP at admission. A single-centre observational cohort study that included patients with TTP from the First Affiliated Hospital of Zhengzhou University in China was conducted from January 1, 2012 to November 30, 2018. The primary outcome was prognosis, including in-hospital mortality, major thromboembolic events, or failure to achieve remission at discharge. We used the random forest method to identify the best set of predictors. Eighty-seven patients with TTP were identified, of whom 12 died during the treatment. The total number of patients within-hospital mortality, major thromboembolic events, and failure to achieve remission at discharge was 58. The machine learning method showed that the D-dimer level was the strongest predictor of the primary outcome. Receiver operating characteristic (ROC) analysis demonstrated that the sensitivity and specificity of the D-dimer level alone for identifying high-risk patients were 78% and 81%, respectively, with an optimum diagnostic cut-off value of 770 ng/mL. The area under the ROC curve (AUC) was 0.80, and the 95% confidence interval (CI) was 0.70 to 0.90. This study found that the D-dimer level exhibited a good predictive ability for prognosis in patients with TTP. These findings may aid in the development of new and intensive treatment strategies to achieve remission among high-risk patients. However, external validation is necessary to confirm the generalizability of our approach across populations and treatment practices.

Reliable methods for enantioselective cis-dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis-α-[Fe

Cobalt(II)-porphyrin catalyzed intramolecular Buchner reaction and arene cyclopropanation of alkyl diazomethanes in situ generated from N-tosylhydrazones to give a range of bicyclic cycloheptatriene fused pyrrolidines and tetracyclic cyclopropane fused pyrrolidines in good to high yields and with high chemo- and regio-selectivity. The obtained cyclopropane fused pyrrolidines can be readily converted to other N-heterocycles with potential synthetic and biological interests.

Exosomes is a key component of cell paracrine secretion and can exert important effects in various disease models. However, the role of exosomes in neuron repair of spinal cord injury (SCI) has rarely been reported. In this study, Exosomes were isolated from cerebrospinal fluid of SCI and normal, and incubated neuron in vitro respectively to research its biological function in cell proliferation. The results demonstrated these exosomes all expressed CD9, CD63, CD81, Alix and Tsg101; however, only exosomes derived from cerebrospinal fluid of SCI could promote proliferation of neuron via ERK signaling pathway, and decrease cell apoptosis. Exosomes contain cytosolic content, including proteins, mRNAs and non-cording RNAs, and play a role in important biological function. Our research showed exosomes derived from cerebrospinal fluid of SCI, they can influence neuron cell proliferation in vitro, we did not observe these characters in exosome derived from normal cerebrospinal fluid.

Reactivity study of novel metal carbene complexes can offer new opportunities in catalytic carbene transfer reactions as well as in other synthetic protocols. Metal complexes with quinoid carbene (QC) ligands are assumed to be key intermediates in a variety of metal-catalyzed QC transfer reactions using diazo quinones, which demands development of the chemistry of QC transfer of well characterized metal-QC complexes. Herein we report the isolation and QC transfer of ruthenium porphyrins [Ru(Por)(QC)] which contribute the first examples of (i) structurally characterized metal-QC complex (by X-ray crystallography) and (ii) isolated metal-QC complex that undergoes QC transfer reaction. The complexes [Ru(Por)(QC)] were prepared from reaction of [Ru(Por)(CO)] with diazo quinones and exhibited dual reactivity, i.e., hydrogen atom transfer (HAT) as well as QC transfer. The stoichiometric QC transfer reactions from these Ru-QC complexes to nitrosoarenes (ArNO) afforded nitrones in up to 90% yield, and the corresponding catalytic reactions were also developed. Both the stoichiometric and catalytic reactions for a series of QC ligands bearing electron-donating and -withdrawing substituents showed a reverse substituent effect on the QC transfer reactivity. Complexes [Ru(Por)(QC)] are also reactive toward C-H and X-H (X = N, S) bonds and can catalyze aerobic oxidation of 1,4-cyclohexadiene; their stoichiometric HAT reactions with unsaturated hydrocarbons gave product yields of up to 88%. The unique dual reactivity and electronic feature of [Ru(Por)(QC)] were studied by spectroscopic means and density functional theory (DFT) calculations.

Correction for ‘Stable group 8 metal porphyrin mono- and bis(dialkylcarbene) complexes: synthesis, characterization, and catalytic activity’ by Hai-Xu Wang et al., Chem. Sci., 2020, 11, 2243–2259, DOI: 10.1039/C9SC05432D.

Laryngeal cancers are mostly squamous cell carcinomas. Although targeting radio-resistant cancer cells is important for improving the treatmental efficiency, the signaling pathway- and therapeutic strategy-related to laryngeal carcinoma still require further study. Galangin is an active pharmacological ingredient, isolated from propolis and Alpinia officinarum Hance, and has been reported to have anticancer and anti-oxidative properties through regulation of cell cycle, resulting in angiogenesis, apoptosis, invasion and migration without triggering any toxicity in normal cells. PI3K/AKT and p38 are important signaling pathways to modulate cancer cell apoptosis and proliferation through caspase-3, NF-κB and mTOR signal pathways. Autophagy is also enhanced by activating LC3s and Beclin 1. In the present study, galangin was found to suppress laryngeal cancer cell proliferation. Also, flow cytometry, immunohistochemical and western blot analysis indicated that cell apoptosis was induced for galangin administration, promoting caspase-3 expression through regulating PI3K/AKT/NF-κB. Furthermore, galangin inhibited laryngeal cancer cell proliferation, related to p38 inactivation by galangin treatment. Additionally, mTOR activation regulated by PI3K/AKT was reduced by galangin, suppressing cancer cell transcription and proliferation. Our data also indicated that the tumor volume and weight in nude mice were reduced for galangin use in vivo accompanied by Ki-67 decrease and TUNEL increase in tumor tissues. Together, our data indicated that galangin has a potential role in suppressing human laryngeal cancer via inhibiting tumor cell proliferation, activating apoptosis and autophagy, which were regulated by p38 and AKT/NF-κB/mTOR pathways, providing a therapeutic strategy for human laryngeal cancer treatment.

To investigate the distributions of HLA-B alleles and estimate their associations with idiopathic male infertility in Chinese Han population.Polymerase chain reaction-sequence-based typing (PCR-SBT) method was used for DNA typing at HLA-B locus in 109 patients with idiopathic male infertility and 152 healthy controls in male Han population of Shaanxi Province, situated in northwestern China.In total, we detected 45 HLA-B alleles in idiopathic infertile patients, 48 HLA-B alleles in control subjects. However, no significant differences of these allelic frequencies were found between the infertile patients and the controls.HLA-B gene was unlikely a major risk factor of idiopathic male infertility in this sample population. As different populations have different HLA polymorphisms, investigation of the relationship of other HLA genes and idiopathic male infertility with larger sample size, is warranted in the future.

Summary Human leucocyte antigen (HLA) is a complex gene family that contains several highly polymorphic genes. Some studies have reported HLA-A gene to have a strong role in idiopathic male infertility in Japanese and Yugoslavia populations. Prompted by these findings, we investigated the distributions of HLA-A gene to ascertain their associations with idiopathic male infertility in Chinese population. Polymerase chain reaction–sequence-based typing (PCR-SBT) method was used for DNA typing at HLA-A locus in 109 patients with idiopathic male infertility and 152 healthy controls in Han male population of Shaanxi Province, situated in north-western China. In total, we detected 23 HLA-A alleles in all infertile patients, 22 HLA-A alleles in control subjects. However, no significant differences of these allelic frequencies were found between the patients and the control subjects, suggesting that the HLA-A gene was unlikely a major risk factor of idiopathic male infertility in this sample population. As different populations have different HLA polymorphisms, investigation into the relationship of other HLA genes and idiopathic male infertility in our population is needed in the future.

To investigate the incidence of single nucleotide polymorphisms in SPO11 and its influence in idiopathic male infertility in China.Infertility factors such as anatomical, immunological and infectious disorders were examined in selecting patients with idiopathic male infertility. Routine semen analysis was performed. DNA was isolated from peripheral blood of the selected patients and control group, and five SNP loci of SPO11 were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Furthermore, nucleotide sequences were sequenced.SNP5 (rs28368082) in the exon7 of SPO11 was identified to be associated with idiopathic male infertility (P = 0.037 for differences across genotypes). A transversion (C5679T) was detected in eight patients (11.0%), which led arginine change into tryptophan. And this variant was not found in the remaining patients and controls.A SPO11 SNP was associated with idiopathic male reproduction, suggested that SPO11 might has an effect on premorbid functioning, which increase susceptibility for idiopathic male reproduction. Further research on this issue is still necessary.

Deubiquitinating enzymes (DUBs) play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 (USP26) is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription (RT)-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids (steps 9-16), Leydig cells and nerve fibers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial cells, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.

Stimulated emission has been observed from oxide structure of silicon when optically excited by 514 nm laser. The twin peaks in the region from 690 nm to 700 nm are dominated by stimulated emission which can be demonstrated by its threshold behavior and transition in linear evolution. The oxide structure was fabricated by laser irradiation and annealing treatment on silicon. A model for explaining the stimulated emission has been proposed in which the trap states of the interface between oxide of silicon and porous nanocrystal play an important role.

Stimulated emission has been observed from oxide structure of silicon when optically excited by 514 nm laser. The photoluminescence (PL) pulse has a Lorentzian shape with a full width at half maximum (FWHM) of 0.5–0.6 nm. The twin peaks at 694 nm and 692 nm are dominated by stimulated emission which can be demonstrated by its threshold behavior and transition from sub-threshold to linear evolution in light emission. The gain coefficient from the evolution of the peak-emission intensity as a function of the optically pumped sample length has been measured. The oxide structure was fabricated by laser irradiation and annealing treatment on silicon. A model for explaining the stimulated emission has been proposed in which the trap states of the interface between oxide of silicon and porous nanocrystal play an important role.

Formaldehyde (FA), a ubiquitous environmental pollutant, has long been suspected of having male reproductive toxicity. However, FA male reproductive toxicity was inconclusive due to dearth of human studies. Therefore, we sought to investigate whether occupational exposure to FA affects semen quality. Semen quality including five conventional parameters and seven kinematics parameters were compared between 114 male workers occupationally exposed to FA and 76 referents. FA exposure index (FEI) was measured and calculated. Our results showed that sperm progressive motility, total sperm motility, VCL, VSL and VAP were statistically significant decreased in FA exposure workers compared with the referents. Moreover, FEI was significantly negative associated with sperm progressive motility (β = −0.19, P = 0.01) and total sperm motility (β = −0.23, P = 0.004). In addition, a significant elevated risk of abnormal sperm progressive motility were observed in both low- (OR = 2.58; 95% CI: 1.11–5.97) and high-FA-exposed group (OR = 3.41; 95% CI: 1.45–7.92) respectively. Furthermore, a significant increased risk was also estimated for abnormal total sperm motility in both low- (OR = 3.21; 95% CI: 1.24–8.28) and high-FA-exposed group (OR = 4.84; 95% CI: 1.83–12.81) respectively. In conclusion, our study revealed the adverse effects of FA occupation exposure on semen quality, especially on sperm motion parameters.

Due to its low encoding complexity, compressed sensing (CS) has gained wide attention in image processing related areas such as image compression, medical imaging and remote sensing. In existing research on CS based image processing, the commonly used sparse representation scheme for image recovery is the discrete wavelet transform (DWT), which is limited by poor directionality and lack of phase space information. What’s more, the structural information of transform-domain coefficients other than pure sparsity is seldom explored. In this paper, to improve the image recovery performance, we propose a new recovery method by adopting the double-density dual-tree complex wavelet transform (DDDT-CWT) as the sparse representation scheme. In addition, the structural characteristics of the DDDT-CWT coefficients are utilized as extra prior knowledge in the recovery process to further improve the recovery quality. Extensive simulation results have been conducted, and the results show that under the same compression ratio, the proposed method has achieved considerable PSNR gain compared with the traditional recovery algorithm.

Formaldehyde (FA) is a ubiquitous environmental pollutant. However, the effects of FA exposure on reproduction are still a matter of scientific controversy. In this study, we assessed the ovarian toxicity of long-term, low-dose FA exposure in rats and explored the potential oxidative stress mechanisms. A total of 30 Sprague-Dawley female rats were randomly allotted to three groups, in which rats were exposed to FA at a dose of 0 mg/m3 (control), 0.5 mg/m3 and 2.46 mg/m3, respectively, by inhalation consecutively for 60 days. The results showed that the ovarian toxicity of FA is dose dependent. Ovarian structure and function in the group of rats exposed to 0.5 mg/m3 FA showed no obvious difference when compared with those in the control group. However, the activity of superoxide dismutase was significantly decreased, whereas the level of malondialdehyde was significantly increased in ovaries of rats exposed to 2.46 mg/m3 FA. Moreover, histopathological results demonstrated that the number and size of mature follicles significantly decreased, vascular congestion and interstitial edema in the ovaries of rats exposed to 2.46 mg/m3 FA. In conclusion, this study may suggest that the FA level of 0.5 mg/m3 can be considered as a safe level for FA exposure, but long-term FA exposure at a dose of 2.46 mg/m3 has a harmful effect on ovary by inducing oxidative stress.

To investigate the effects of experimental left varicocele (ELV) on the vascular endothelial growth factor (VEGF) and its receptor fms-like tyrosine kinase-1 (Flt-1) proteins in the testis and epididymis of adolescent rats, and to find out the correlation of the two proteins with varicocele-induced male infertility.We established the ELV model in adolescent male SD rats, and detected the expressions of VEGF and Flt-1 proteins in the testis and epididymis by immunohistochemistry at 2 and 4 weeks after surgery.Cell- and region-specific expressions of VEGF and Flt-1 were observed in the testis and epididymis of the ELV and control groups. Statistical analysis showed that, in comparison with the corresponding control groups, the 2- and 4-week ELV groups exhibited a notable increase in the VEGF protein expression in the hibateral testis and epididymis (P0.01, P0.05); the Flt-1 expression was obviously upregulated in the hibateral testis and epididymis of the 2-week ELV group (P0.01, P0.01), but remarkably reduced in the hibateral testis and left epididymis of the 4-week ELV group (P0.01, P0.05), with no statistic difference in the right epididymis (P0.05).ELV can cause changes in the expressions of VEGF and Flt-1 proteins in the testis and epididymis of adolescent rats, and consequently affect spermatogenesis and spermiotelcosis, which may be one of the causes of varicocele-induced male infertility or subfertility.

Androgen receptor (AR) mediates a wide range of cellular processes, such as proliferation, differentiation and apoptosis. Here we sought to identify whether AR was located in pancreatic beta-cells and investigate its functions in type 1 diabetes induced by multiple low doses of streptozotocin. Double/triple immunofluorescence, Western blot and semi-quantitative RT-PCR were carried out to determine variances of AR expression in beta-cells and correlation between AR and apoptosis/proliferation of beta-cells with progress of diabetes. In addition, in vitro primary beta-cells from control mice were cultured for 3 days or 6 days with compound stimulation in order to further identify effect of AR on beta-cell apoptosis and proliferation. AR expression in beta-cells peaked in control and 1-day diabetic mice, gradually and significantly decreased, even disappeared in diabetic mice with progress of diabetes. TUNEL-positive beta-cells were concomitant with overexpression of AR, and Ki67-positive beta-cells showed extremely weak, even negative AR staining. In vitro, AR could mediate beta-cell apoptosis, and AR antagonist flutamide contributed to beta-cell proliferation. In conclusion, AR is abundantly expressed in pancreatic beta-cell cytoplasm of control mice. With progress of type 1 diabetes, decrement of AR expression in diabetic mice contributes to prohibit beta-cells from apoptosis, and is strongly associated with beta-cell proliferation.

We have demonstrated a stimulated photoluminescence (PL) at 694 and 692nm whose emission peak has a Lorentzian shape with a full width at half maximum of 0.5–0.6nm. This stimulated emission comes from the nanostructures on porous silicon oxidized fabricated by irradiation and annealing treatment. Controlling the time of annealing can produce a good coherent emission. A model has been proposed for explaining the stimulated emission in which the trap states of the interface between oxide of silicon and porous nanocrystal play an important role. Calculation shows that trap electronic states appear in the energy gap of the smaller nanocrystal when SiO bonds or Si–O–Si bonds are formed. In the theoretical model, the most important factor in the enhancement and pinning effect of PL emission is the relative position between the level of the trap states and the level of the photoexcitation in the silicon nanocrystal.