Biomechanical stability of oblique lateral interbody fusion combined with four types of internal fixations: finite element analysis

Objective: Using finite element analysis to identify the optimal internal fixation method for oblique lateral lumbar interbody fusion (OLIF), providing guidance for clinical practice.Methods: A finite element model of the L4 – L5 segment was created. Five types of internal fixations were simulated in the generated L4-L5 finite element (FE) model. Then, six loading scenarios, i.e., flexion, extension, left-leaning, right-leaning, rotate left, and rotate right, were simulated in the FE models with different types of fixations. The biomechanical stability of the spinal segment after different fixations was investigated.Results: Regarding the range of motion (ROM) of the fused segment, OLIF + Bilateral Pedicle Screws (BPS) has a maximum ROM of 1.82° during backward bending and the smallest ROM in all directions of motion compared with other models. In terms of the von Mises stress distribution on the cage, the average stress on every motion direction of OLIF + BPS is about 17.08MPa, and of OLIF + Unilateral Vertebral Screw - Pedicle Screw (UVS-PS) is about 19.29 MPa. As for the von Mises stress distribution on the internal fixation, OLIF + BPS has the maximum internal fixator stress in left rotation (31.85 MPa) and OLIF + Unilateral Pedicle Screw (UPS) has the maximum internal fixator stress in posterior extension (76.59 MPa). The data of these two models were smaller than those of other models.Conclusion: OLIF + BPS provides the greatest biomechanical stability, OLIF + UPS has adequate biomechanical stability, OLIF + UVS-PS is inferior to OLIF + UPS synthetically, and OLIF + Double row vertical screw (DRVS) and Individual OLIF (IO) do not present significant obvious advantages

Prevalence of Prostatitis-Like Symptoms and Outcomes of NIH-CPSI in Outpatients with Lifelong and Acquired PE: Based on a Large Cross-Sectional Study in China

Premature ejaculation (PE) is one of the most common sexual dysfunctions, which were associated with prostatitis-like symptoms (PLS). We intended to explore the prevalence of prostatitis-like symptoms and outcomes of National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) scores in outpatients with lifelong (LPE) and acquired premature ejaculation (APE). From December 2013 to December 2015, a total of 498 consecutive heterosexual men with PE and 322 male healthy subjects without PE were enrolled. Each of them completed a detailed questionnaire on demographics information, sexual and medical histories, and the NIH-CPSI. Assessment of NIH-CPSI and definition of PLS and PE were used to measure the PLS and NIH-CPSI scores and ejaculatory function for all subjects. Finally, a total of 820 subjects (including 498 men in PE group and 322 men in control group) were enrolled in our study. The mean ages were significantly different between PE and no PE groups. Men with PE reported worse PLS and higher NIH-CPSI scores (P < 0.001 for all). Similar findings were also observed between men with LPE and APE. Men with APE also reported higher rates of PLS and scores of NIH-CPSI (P < 0.001 for all). Multivariate analysis showed that PLS and NIH-CPSI scores were significantly associated with PE

Research Progress and Development Prospects of Enhanced GaN HEMTs

With the development of energy efficiency technologies such as 5G communication and electric vehicles, Si-based GaN microelectronics has entered a stage of rapid industrialization. As a new generation of microwave and millimeter wave devices, High Electron Mobility Transistors (HEMTs) show great advantages in frequency, gain, and noise performance. With the continuous advancement of material growth technology, the epitaxial growth of semiconductor heterojunction can accurately control doping level, material thickness, and alloy composition. Consequently, HEMTs have been greatly improved from material structure to device structure. Device performance has also been significantly improved. In this paper, we briefly describe MOCVD growth technology and research progress of GaN HEMT epitaxial films, examine and compare the “state of the art” of enhanced HEMT devices, analyze the reliability and CMOS compatibility of GaN devices, and look to the future directions of possible development

Altered miRNA profile in testis of post-cryptorchidopexy patients with non-obstructive azoospermia

Abstract Background Cryptorchidism is one of the most common causes of non-obstructive azoospermia (NOA) leading to male infertility. Despite various medical approaches been utilised, many patients still suffer from infertility. MicroRNAs (miRNAs) play vital roles in the progress of spermatogenesis; however, little is known about the miRNA expression profile in the testes. Therefore, the miRNA profile was assessed in the testis of post-cryptorchidopexy patients. Methods Three post-cryptorchidopexy testicular tissue samples from patients aged 23, 26 and 28 years old and three testis tissues from patients with obstructive azoospermia (controls) aged 24, 25 and 36 years old were used in this study. Next-generation sequencing (NGS) was used to perform the miRNA expression profiling. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assays were subsequently used to confirm the results of several randomly-selected and annotated miRNAs. Results A series of miRNAs were found to be altered between post-cryptorchidopexy testicular tissues and control tissues, including 297 downregulated and 152 upregulated miRNAs. In the subsequent qRT-PCR assays, the expression levels of most of the selected miRNAs (9/12, P < 0.05) were consistent with the results of NGS technology. Furthermore, signal transduction, adaptive immune response and biological regulation were associated with the putative target genes of the differentially-expressed miRNAs via GO analysis. In addition, oxidative phosphorylation, Parkinson’s disease and ribosomal pathways were shown to be enriched using KEGG pathway analysis of the differentially-expressed genes. Conclusions This study provides a global view of the miRNAs involved in post-cryptorchidopexy testicular tissues as well as the altered expression of miRNAs compared to control tissues, thus confirming the vital role of miRNAs in cryptorchidism

Reduction of Compton Background Noise for X-ray Fluorescence Computed Tomography with Deep Learning

For bench-top X-ray fluorescence computed tomography (XFCT), the X-ray tube source will bring extreme Compton background noise, resulting in a low signal-to-noise ratio and low contrast detection limit. In this paper, a noise2noise denoising algorithm based on the UNet deep learning network is proposed. The network can use noise image learning to convert the noise image into a clean image. Two sets of phantoms (high concentration Gd phantom and low concentration Bi phantom) are used for scanning to simulate the imaging process under different noise levels and generate the required data set. Additionally, the data set is generated by Geant4 simulation. In the training process, the L1 loss function is used for its good convergence. The image quality is evaluated according to CNR and pixel profile, which shows that our algorithm is better than BM3D, both visually and quantitatively

miR-34c disrupts spermatogonial stem cell homeostasis in cryptorchid testes by targeting Nanos2

Abstract Background Cryptorchidism as a common genitourinary malformation with the serious complication of male infertility draws widespread attention. With several reported miRNAs playing critical roles in spermatogonial stem cells (SSCs), we aimed to explore the fundamental function of the highly conserved miR-34c in cryptorchidism. Methods To explore whether miR-34c participates in spermatogenesis by regulating Nanos2, we examined the effect of overexpression and inhibition for miR-34c on Nanos2 expression in GC-1 cells. Moreover, the expression levels of miR-34c and Nanos2 with cryptorchidism in humans and mice were examined. Furthermore, the homeostasis of SSCs was evaluated through counting the number of promyelocytic leukemia zinc finger (PLZF) positive spermatogonia in murine cryptorchid testes. Results In the present study, we show that miR-34c could inhibit the expression of Nanos2 in GC-1 cells. Meanwhile, miR-34c significantly decreased in both the testicular tissues of patients with cryptorchidism and surgery-induced murine model of cryptorchidism. Western blot revealed that the protein level of Nanos2 was up-regulated and showed to be negatively correlated to the expression of miR-34c in our model. The abnormal expression of miR-34c/Nanos2 disrupted the balance between SSC self-renewal and differentiation, eventually damaging the spermatogenesis of cryptorchid testes. Conclusions The miR-34c/Nanos2 pathway provides new insight into the mechanism of male infertility caused by cryptorchidism. Our results indicate that miR-34c may serve as a biological marker for treatment of infertility caused by cryptorchidism

Electro-photoluminescence study in InGaAs/AlGaAs multi-quantum-wells

Photoluminescence (PL) plays an important role in the study of luminescence characteristics of multi-quantum-well (MQW) structures. In this work, we study electro-photoluminescence spectra of InGaAs/AlGaAs MQWs under open-circuit, short-circuit, and forward-voltage conditions. The dependences of photocurrent and photovoltage on excitation power are discussed in this paper, which allows us to explore the carrier behavior in InGaAs/AlGaAs MQW LEDs deeply. We propose that the photovoltaic effect in open-circuit (OC) conditions should be properly considered for PL characterization and calculation of the internal quantum efficiency (IQE) as well as non-radiative recombination (NRA) efficiency in InGaAs/AlGaAs MQW LEDs