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To isolate low-frequency vibration, a novel single-degree-of-freedom vibration isolation system with quasi-zero stiffness (QZS) and nonlinear damping using geometric nonlinearity is proposed in this study. One of the remarkable features of this system is the use of scissor-like structures (SLSs) to achieve the nonlinear stiffness and damping. The length difference between the connecting rods in SLS is considered. First, both the stiffness and damping characteristics are derived and analyzed in detail. Then, the frequency response and force transmissibility are obtained using the harmonic balance method. Finally, the effects of structural parameters on the isolation performance are investigated. Theoretical results show that the proposed QZS vibration system can not only isolate low-frequency vibration but also suppress the high-amplitude vibration in the resonant region. Besides, increasing nonlinear damping has little influence on the isolation performance in high frequencies. The proposed QZS vibration system can outperform a classical counterpart. [ABSTRACT FROM AUTHOR]

The study aimed to assess the biocompatibility and efficacy of a prostatic urethral lift (PUL) for benign prostatic hyperplasia (BPH). Human BPH-1 cells were co-cultured with implant anchors and sutures, and cytotoxicity was measured. Scanning electron microscopy (SEM) was used to observe adhesion and growth of cells and to evaluate implant biocompatibility. Fifteen male beagle dogs were randomly assigned to the surgical (n = 9) or sham-operated (n = 6) groups. The surgical group underwent cystotomy, and PUL was used to insert two implants in each lobe of the prostate to compress the enlarged prostate and dilate the urethra; the sham group underwent cystotomy without implant insertion. Compared with the control group, no significant difference in cell viability among the groups with different co-culture times of implant anchors and sutures (P > 0.05) was observed. SEM revealed good adhesion and growth of prostate cells on the implants. Improvements in urine flow rates remained stable at 7, 28, and 180 days after surgery, and the urethral diameter in the prostate region was significantly increased compared with that before surgery. PUL is a biocompatible and effective treatment for BPH, improving the urine flow rate without causing inflammation, tissue damage, or cytotoxic effects. Here, the basis for further PUL application was provided. [ABSTRACT FROM AUTHOR]

Amylose, one of the components of starch, is a glucose polymer consisting largely of long, linear chains with a few long-chain branch points. The chain-length (molecular weight) distribution (CLD) of the component chains of amylose can provide information on amylose biosynthesis-structure-property relations, as has been done previously by fitting amylopectin CLDs to a model with physically meaningful parameters. Due to the presence of long chains, the CLD of amylose can currently best be obtained by size-exclusion chromatography, a technique that suffers from band-broadening effects which alter the observed distribution. The features of the multiple regions present in amylose chain-length distributions are also difficult to resolve, an issue that combines with band broadening to compound the difficulty of analysis and subsequent parameterization of the structural characteristics of amylose. A new method is presented to fit these distributions with biologically meaningful parameters in a way that accounts for band broadening. This is achieved by assuming that band broadening takes the form of a simple Gaussian over a relatively small region and that chain stoppage is a random process independent of the length of the substrate chain over the same region; these assumptions are relatively weak and expected to be frequently applicable. The method provides inbuilt consistency tests for its applicability to a given data set and, in cases where it is applicable, allows for the first nonempirical parameterization of amylose biosynthesis-structure-property relations from CLDs by using parameters directly linked to the activities of the enzymes responsible for chain growth and chain stoppage. [ABSTRACT FROM AUTHOR]

The study aimed to assess the biocompatibility and efficacy of a prostatic urethral lift (PUL) for benign prostatic hyperplasia (BPH). Human BPH-1 cells were co-cultured with implant anchors and sutures, and cytotoxicity was measured. Scanning electron microscopy (SEM) was used to observe adhesion and growth of cells and to evaluate implant biocompatibility. Fifteen male beagle dogs were randomly assigned to the surgical (n = 9) or sham-operated (n = 6) groups. The surgical group underwent cystotomy, and PUL was used to insert two implants in each lobe of the prostate to compress the enlarged prostate and dilate the urethra; the sham group underwent cystotomy without implant insertion. Compared with the control group, no significant difference in cell viability among the groups with different co-culture times of implant anchors and sutures (P > 0.05) was observed. SEM revealed good adhesion and growth of prostate cells on the implants. Improvements in urine flow rates remained stable at 7, 28, and 180 days after surgery, and the urethral diameter in the prostate region was significantly increased compared with that before surgery. PUL is a biocompatible and effective treatment for BPH, improving the urine flow rate without causing inflammation, tissue damage, or cytotoxic effects. Here, the basis for further PUL application was provided. [ABSTRACT FROM AUTHOR]

In cancer radiation therapy, large tumor motion due to respiration can lead to uncertainties in tumor target delineation and treatment delivery, thus making active motion management an essential step in thoracic and abdominal tumor treatment. In current practice, patients with tumor motion may be required to receive two sets of CT scans – the initial free-breathing 4-dimensional CT (4DCT) scan for tumor motion estimation and a second CT scan under appropriate motion management such as breath-hold or abdominal compression. The aim of this study is to assess the feasibility of a predictive model for tumor motion estimation in three-dimensional space based on machine learning algorithms. The model was developed based on sixteen imaging features extracted from non-4D diagnostic CT images and eleven clinical features extracted from the Electronic Health Record (EHR) database of 150 patients to characterize the lung tumor motion. A super-learner model was trained to combine four base machine learning models including the Random Forest, Multi-Layer Perceptron, LightGBM and XGBoost, the hyper-parameters of which were also optimized to obtain the best performance. The outputs of the super-learner model consist of tumor motion predictions in the Superior-Inferior (SI), Anterior-Posterior (AP) and Left-Right (LR) directions, and were compared against tumor motions measured in the free-breathing 4DCT scans. The accuracy of predictions was evaluated using Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) through ten rounds of independent tests. The MAE and RMSE of predictions in the SI direction were 1.23 mm and 1.70 mm; the MAE and RMSE of predictions in the AP direction were 0.81 mm and 1.19 mm, and the MAE and RMSE of predictions in the LR direction were 0.70 mm and 0.95 mm. In addition, the relative feature importance analysis demonstrated that the imaging features are of great importance in the tumor motion prediction compared to the clinical features. Our findings indicate that a super-learner model can accurately predict tumor motion ranges as measured in the 4DCT, and could provide a machine learning framework to assist radiation oncologists in determining the active motion management strategy for patients with large tumor motion. [ABSTRACT FROM AUTHOR]

This paper investigates the volumetric, microstructural, and shear behaviours of an expansive soil during multiple drying-wetting (DW), freeze–thaw (FT), and drying-wetting-freeze–thaw (DWFT) cycles. Specimens compacted at natural moisture content and dry density were subjected to 1, 4, 6, and 10 DW, FT, or DWFT cycles. Volumetric changes were recorded during the treatments and mercury intrusion porosimetry, and scanning electron microscope tests were conducted to observe the soil's microstructure before and after treatments. As compacted specimens and specimens after different numbers of DW, FT, and DWFT cycles were saturated and sheared under consolidated undrained condition to determine their undrained elastic modulus (Eu), shear strength (qu), total cohesion (c), and friction angle (ϕ). Experimental results show that DW, FT, and DWFT cycles mainly influence the soil's macropores with diameters between 5 and 250 μm. Macropores collapse during DW cycles, which lead to collapse in the soil's global volume. Cracks develop during FT cycles and result in slight swelling in the soil's volume. These two effects offset during DWFT cycles and cause an intermediate volumetric behaviour. The Eu, qu, c, and ϕ decline during DW, FT, and DWFT cycles, and the reduction was most significant during DWFT cycles. They reach an equilibrium after approximately 6 cycles of treatment. A simple normalized model was developed to describe the stress–strain curves considering the influence of DW, FT, and DWFT cycles. Good agreements were achieved between the model predictions and measurements for all stress–strain curves obtained in this study. [ABSTRACT FROM AUTHOR]

The quantum quench dynamics of the one-dimensional Ising model in transverse field is investigated using the quantum renormalisation group method. The analytic expression of concurrence C(t) is obtained, where the initial state is a superposition state which is constructed from the eigenstates of pure Ising system. The effect of parameter a in the period and range of concurrence are exhibited respectively in the vicinity of the critical point, which show scaling behaviour. When effective magnetic field g is big enough, the maximum limit value is 1.0. However, the minimum value is different, which is also dependent on the evolved time t. [ABSTRACT FROM AUTHOR]

Investigating gene function relies on the efficient manipulation of endogenous gene expression. Currently, a limited number of tools are available to robustly manipulate endogenous gene expression between "on" and "off" states. In this study, we insert a 63 bp coding sequence of T3H38 ribozyme into the 3' untranslated region (UTR) of C. elegans endogenous genes using the CRISPR/Cas9 technology, which reduces the endogenous gene expression to a nearly undetectable level and generated loss-of-function phenotypes similar to that of the genetic null animals. To achieve conditional knockout, a cassette of loxP-flanked transcriptional termination signal and ribozyme is inserted into the 3' UTR of endogenous genes, which eliminates gene expression spatially or temporally via the controllable expression of the Cre recombinase. Conditional endogenous gene turn-on can be achieved by either injecting morpholino, which blocks the ribozyme self-cleavage activity or using the Cre recombinase to remove the loxP-flanked ribozyme. Together, our results demonstrate that these ribozyme-based tools can efficiently manipulate endogenous gene expression both in space and time and expand the toolkit for studying the functions of endogenous genes. Manipulation of endogenous genes in space and time in C. elegans is accomplished by inserting a ribozyme sequence into the 3'UTR with CRISPR/Cas9, utilizing self-cleavage of the ribozyme and Cre/loxP system as an "off and "on" switch, respectively. [ABSTRACT FROM AUTHOR]

The photovoltaic performance of mesoscopic perovskite solar cells (PSCs) is strongly dependent on the interface between perovskite and electron transport layer. Herein, an attempt to load facile processed ZnO quantum dots (ZQDs) or TiO2 quantum dots (TQDs) into the mesoporous TiO2 (mp-TiO2) layer via a simple spin coating method was performed. Both of them had huge impact on the morphology of perovskite films, leading to larger perovskite grains. However, the power conversion efficiency (PCE) of these two kinds of QDs modified cells exhibited a different tendency. The champion PCE of ZQDs modified PSCs was remarkably improved from 14.54 to 17.2%, while for that of TQDs modified ones decreased to 11.78%. It was demonstrated that the enhanced PCE and short-circuit current (Jsc) were attributed to the enlarged grain size and enhanced light absorption of perovskite film, faster electron extraction and transport as well as less recombination for ZQDs modified PSCs, which mainly resulted from the increased active specific surface area. On the contrary, the deterioration of TQDs modified PSCs was ascribed to the aggregation of TQDs, which sharply decreased the specific surface area of the electron transport layer. This work provided an efficient and facile way to improve the photovoltaic performance of mesoscopic PSCs. [ABSTRACT FROM AUTHOR]

HIV-1 Tat is known to be neurotoxic and important for HIV/neuroAIDS pathogenesis. However, the overwhelming majority of the studies involved use of recombinant Tat protein. To understand the contributions of Tat protein to HIV/neuroAIDS and the underlying molecular mechanisms of HIV-1 Tat neurotoxicity in the context of a whole organism and independently of HIV-1 infection, a doxycycline-inducible astrocyte-specific HIV-1 Tat transgenic mouse (iTat) was created. Tat expression in the brains of iTat mice was determined to be in the range of 1-5 ng/ml and led to astrocytosis, loss of neuronal dendrites, and neuroinflammation. iTat mice have allowed us to define the direct effects of Tat on astrocytes and the molecular mechanisms of Tat-induced GFAP expression/astrocytosis, astrocyte-mediated Tat neurotoxicity, Tat-impaired neurogenesis, Tat-induced loss of neuronal integrity, and exosome-associated Tat release and uptake. In this review, we will provide an overview about the creation and characterization of this model and its utilities for our understanding of Tat neurotoxicity and the underlying molecular mechanisms. [ABSTRACT FROM AUTHOR]

Small cell lung cancer (SCLC) is classified as a high-grade neuroendocrine (NE) tumor, but a subset of SCLC has been termed "variant" due to the loss of NE characteristics. In this study, we computed NE scores for patient-derived SCLC cell lines and xenografts, as well as human tumors. We aligned NE properties with transcription factor-defined molecular subtypes. Then we investigated the different immune phenotypes associated with high and low NE scores. We found repression of immune response genes as a shared feature between classic SCLC and pulmonary neuroendocrine cells of the healthy lung. With loss of NE fate, variant SCLC tumors regain cell-autonomous immune gene expression and exhibit higher tumor-immune interactions. Pan-cancer analysis revealed this NE lineage-specific immune phenotype in other cancers. Additionally, we observed MHC I re-expression in SCLC upon development of chemoresistance. These findings may help guide the design of treatment regimens in SCLC. Ling Cai et al. used transcriptomic profiling data of healthy lung, patient-derived small cell lung cancer cell lines, xenografts, and primary tumors to examine a link between neuroendocrine (NE) signatures and immune gene expression. Their findings suggest that cell-autonomous immune gene repression is a shared feature between healthy and tumor cells of NE lineage and may influence tumor-immune cell interaction and response to immunotherapy. [ABSTRACT FROM AUTHOR]

The aim of this study was to screen out a bacillus from Sichuan sun vinegar grains capable of producing a high total amount of flavonoids and total phenols. Forty-eight strains were initially screened out from Sichuan sun vinegar grains. The sodium nitrite-aluminum nitrate-sodium hydroxide colorimetry method was used to determine the total flavonoids, and the Folin-phenol method was used to determine the total phenols. Based on the results of total flavonids and total phenol producing capacities of the strains, one strain was singled out for use in this study. This strain, which was named YB-19, is capable of producing a total amount of 96.55 μg/mL flavonoids and 86.69 μg/mL phenols. YB-19 was identified by its strain morphology, physiological and biochemical characteristics. DNA sequencing was performed on YB-19. The results of the DNA sequencing showed that the sequence similarity between strain YB-19 and Bacillus toyonensis strain BCT-7112 was 99 %, and the two strains were housed on the same branch in the phylogenetic tree. Combined with the results of the strain morphology and the observed physiological and biochemical characteristics, YB-19 was identified as B. toyonensis. The screened strain YB-19 can be applied to the traditional brewing process of sun vinegar to improve vinegar quality and to enrich the microbial resources for vinegar fermentation. [ABSTRACT FROM AUTHOR]

Glycosylation of hydrophobic peptides at one terminus effectively increases their water-solubility, and conjugation through the opposing end to a carrier protein, renders them more immunogenic. Moreover, the glycosylation minimizes antibody responses to potentially deleterious, non-productive terminal neo-epitope regions of the peptides, and consequently shifts peptide immunogenicity towards the core amino acid residues. As proof of concept, glycopeptide-protein conjugates related to influenza hemagglutinin (HA), neuraminidase (NA), and the dimerization loop region of human epidermal growth factor receptor 2 (Her2), demonstrated a favorable production of core peptide specific antibodies as determined by ELISA studies. Furthermore, glycosylated Her2 peptide conjugate antisera were also shown to recognize full length Her2 protein by ELISA and at the cell surface through flow cytometry analysis. In contrast, unmasked peptide conjugates generated significant antibody populations that were specific to the terminal neo-epitope of the peptide immunogen that are notably absent in parental proteins. Antibodies generated in this manner to peptides in the dimerization loop of Her2 are also functional as demonstrated by the growth inhibition of Her2 expressing SKBR3 carcinoma cells. This method provides a technique to tailor-make epitope-specific antibodies that may facilitate vaccine, therapeutic and diagnostic antibody development. [ABSTRACT FROM AUTHOR]