Pressure relief of underground ammunition storage under missile accidental ignition

Safety of underground ammunition storage is an important issue,especially during the accidental ignition of missiles.This work investigates the pressure and temperature distribution of the multi-layer underground ammunition storage with a pressure relief duct during the accidental ignition process of the missile.A large-scale experiment was carried out using a multi-layered restricted space with a pressure relief duct to simulate the underground ammunition store and a solid rocket motor to simulate the accidental ignition of the missile.The results show that when the motor gas mass flow increased by5.6 times,the maximum pressure of the ammunition storage increased by 5.87 times.At a certain motor flow rate,when the pressure relief exhaust area at the end of the relief duct was reduced by 1/2,the maximum pressure on the first layer did not change.But the rate of pressure relief was reduced and the time delayed for the pressure of ammunition store to drop to zero.In this experiment,when the motor ignition position was located in to the third layer ammunition chamber,the maximum pressure was reduced by 32.9%and also reduced the rate of change of pressure.In addition,for the experimental conditions,the theoretical analysis of the pressure relief of the ammunition storage is given by a simplified model.Based on the findings,some suggestions to the safety protection design of ammunition store are proposed.

Development of a predictive model for increasing sperm retrieval sucpess by microdissection testicular sperm extraction in patients with nonobstructive azoospermia

Microdissection testicular sperm extraction(micro-TESE)is widely used to treat nonobstructive azoospermia.However,a good prediction model is required to anticipate a successful sperm retrieval rate before performing micro-TESE.This retrospective study analyzed the clinical records of 200 nonobstructive azoospermia patients between January 2021 and December 2021.The backward method was used to perform binary logistic regression analysis and identify factors that predicted a successful micro-TESE sperm retrieval.The prediction model was constructed using acquired regression coefficients,and its predictive performance was assessed using the receiver operating characteristic curve.In all,67 patients(sperm retrieval rate:33.5%)underwent successful micro-TESE.Follicle-stimulating hormone,anti-Miillerian hormone,and inhibin B levels varied significantly between patients who underwent successful and unsuccessful micro-TESE.Binary logistic regression analysis yielded the following six predictors:anti-Mullerian hormone(odds ratio[OR]=0.902,95%confidence interval[Cl]:0.821-0.990),inhibin B(OR=1.012,95%Cl:1.001-1.024),Klinefelter’s syndrome(OR=0.022,95%Cl:0.002-0.243),Y chromosome microdeletion(OR=0.050,95%Cl:0.005-0.504),cryptorchidism with orchiopexy(OR=0.085,95%Cl:0.008-0.929),and idiopathic nonobstructive azoospermia(OR=0.031,95%Cl:0.003-0.277).The prediction model had an area under the curve of 0.720(95%Cl:0.645-0.794),sensitivity of 65.7%,specificity of 72.2%,Youden index of 0.379,and cut-off value of 0.305 overall,indicating good predictive value and accuracy.This model can assist clinicians and nonobstructive azoospermia patients in decision-making and avoiding negative micro-TESE results.

Nanotechnology-assisted adipose-derived stem cell （ADSC） therapy for erectile dysfunction of cavernous nerve injury： In vivo cell tracking, optimized injection dosage, and functional evaluation

Stem cell therapy is a potentially promising option for erectile dysfunction; however, its risk of tumorigenicity is a clinical hurdle and the risk is positively related to the number of injected cells. Our previous study showed that nanotechnology improved adipose-derived stem cell （ADSC） therapy for erectile dysfunction of cavernous nerve injury （CNI） by attracting cells in the corpus cavernosum. These results indicated the possibility of using a reduced dosage of ADSCs for intracavernous injection. In this exploratory study, we used lower dosage （2 × 105 cells） of ADSCs for intracavernous injection （ICI） and the nanotechnology approach. Intracavernous pressure and mean arterial pressure were measured at day 28 to assess erectile function. The low-dose ADSC therapy group showed favorable treatment effects, and nanotechnology further improved these effects. In vivo imaging of ICI cells revealed that the fluorescein signals of NanoShuttle-bound ADSCs （NanoADSCs） were much stronger than those of ADSCs at days 0, 1, and 3. Both immunofluorescence and Western blot analysis showed a significant increase in smooth muscle, endothelium, and nerve tissue in the ADSC group compared to that in the CNI group; further improvement was achieved with assisted nanotechnology. These findings demonstrate that nanotechnology can be used to further improve the effect of small dosage of ADSCs to improve erectile function. Abundant NanoADSCs remain in the corpus cavernosum in vivo for at least 3 days. The mechanism of erectile function improvement may be related to the regeneration of the smooth muscle, endothelium, and nerve tissues.

Altered microRNA profiles of testicular biopsies from patients with nonobstructive azoospermia

Many studies have shown that microRNAs(miRNAs)play vital roles during the spermatogenesis.However,little is known about the altered miRNA profiles of testicular tissues in nonobstructive azoospermia(NOA).Using microarray technology,the miRNA expression profiles of testicular biopsies from patients with NOA and of normal testicular tissues were determined.Bioinformatics analyses were conducted to predict the enriched biological processes and functions of identified miRNAs.The microarray data were validated by quantitative reverse transcriptase polymerase chain reaction(qRT-PCR),the results of which were then validated with a larger sample size.Correlations between the miRNA expression levels and clinical characteristics were analyzed.Receiver operating characteristic(ROC)curve analysis was used to evaluate the diagnostic ability of miRNAs for azoospermia.Hierarchical clustering showed that 129 miRNAs were significantly differentially expressed between the NOA and control groups.Bioinformatics analysis indicated that the differentially expressed miRNAs were involved in spermatogenesis,cell cycle,and mitotic prometaphase.In the subsequent qRT-PCR assays,the selected miRNA expression levels were consistent with the microarray results,and similar validated results were obtained with a larger sample size.Some clinical characteristics were significantly associated with the expression of certain miRNAs.In particular,we identified a combination of two miRNAs(miR-10b-3p and miR-34b-5p)that could serve as a predictive biomarker of azoospermia.This study provides altered miRNA profiles of testicular biopsies from NOA patients and examines the roles of miRNAs in spermatogenesis.These profiles may be useful for predicting and diagnosing the presence of testicular sperm in individuals with azoospermia.

RNAs in the testicular tissue of patients with non-obstructive azoospermia

Circular RNAs(circRNAs)are highly conserved and ubiquitously expressed noncoding RNAs that participate in multiple reproductionrelated diseases.However,the expression pattern and potential functions of circRNAs in the testes of patients with non-obstructive azoospermia(NOA)remain elusive.In this study,according to a circRNA array,a total of 37881 circRNAs were identified that were differentially expressed in the testes of NOA patients compared with normal controls,including 19874 upregulated circRNAs and 18007 downregulated circRNAs.Using quantitative real-time polymerase chain reaction(qRT-PCR)analysis,we confirmed that the change tendency of some specific circRNAs,including hsa_circ_0137890,hsa_circ_0136298,and hsa_circ_0007273,was consistent with the microarray data in another larger sample.The structures and characteristics of these circRNAs were confirmed by Sanger sequencing,and fluorescence in situ hybridization revealed that these circRNAs were primarily expressed in the cytoplasm.Bioinformatics analysis was used to construct the competing endogenous RNA(ceRNA)network,and numerous miRNAs that could be paired with circRNAs validated in this study were reported to be vital for spermatogenesis regulation.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses indicated that genes involved in axoneme assembly,microtubule-based processes,and cell proliferation were significantly enriched.Our data suggest that there are aberrantly expressed circRNA profiles in patients with NOA and that these circRNAs may help identify key diagnostic and therapeutic molecular biomarkers forNoA patients.

Fertility achieved through in vitro fertilization in a male patient with 48,XXYY syndrome

The 48,XXYY syndrome is a rare sex chromosome aneuploidy with an incidence of 1：18 000-1：40 000 male births and is associated with hypergonadotropic hypogonadism as an endocrine disorder. Most men with this syndrome are never diagnosed in China. Due to sex chromosome aneuploidies and limited effective communication, these patients suffer from infertility.