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Determination of the cracking behavior during crack propagation helps to better understand damage and fracture processes in brittle rocks. The paper studies the cracking behavior of rocks on three scales: macro-deformation (or macro-cracking), internal micro-fracture, and surface crack coalescence. Under uniaxial compression, the cracking behavior of two types of sandstone specimens having single flaws was experimentally and systematically investigated. Acoustic emission (AE) and three-dimensional digital image correlation (3D-DIC) techniques were utilized to continuously monitor the acoustic shock signals generated by micro-fracture events inside the specimen and the specimen surface cracking process. The experimental results show that at the crack initiation stage, many micro-tensile fractures within the rock are initiated and coalesced, and small strain localized zones (SLZs) appear on the specimen surface. In the crack propagation stage, micro-fractures coalesce into macro-fractures that propagate in tensile mode to form surface cracks, which finally break in tension or slide against each other in shear mode. The formation of SLZs is related to the dip angle of pre-existing flaws, which determines the direction and mode of crack propagation. In conclusion, the strong acoustic-optical evidence accompanying different cracking behaviors is discussed in detail. From both acoustic and optical perspectives, it reveals and explains how flaws and material properties affect the strength and cracking mechanisms of brittle rocks. The study aids comprehension of the potential relation between internal micro-fracture and surface cracking in the process of engineering rock mass failure.

The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) represents a significant economic zone with a diverse financial landscape. Understanding the spatial distribution of financial resources within this area is crucial for promoting balanced economic growth and financial development. This study investigates the spatial patterns of financial agglomeration in the GBA, identifying key influencing factors and assessing their impact on the region's financial landscape. We employ the entropy value method to evaluate financial agglomeration levels across the GBA's cities. Additionally, we use spatial econometric techniques to analyze the spatial correlations and the Geo-Detector model to determine the primary factors influencing financial agglomeration. The analysis reveals an overall increase in financial agglomeration, with significant disparities among cities. Key factors driving this agglomeration include transportation infrastructure, overseas trade, foreign direct investment (FDI), and technological advancements. Hong Kong and Shenzhen display notable unevenness in the distribution of financial industries. The interplay between finance, technology, and industrial sectors suggests considerable development potential. Understanding and optimizing the spatial distribution of financial resources is essential for fostering high-quality financial development and sustainable economic growth in the GBA. This study provides insights that can inform policy decisions aimed at enhancing financial integration and cooperation within the region.

Liver fibrosis is the excessive accumulation of extracellular matrix proteins, which is mainly caused by accumulation of activated hepatic stellate cells (HSCs). The mechanisms of activation and proliferation of HSCs, two key events after liver damage, have been studied for many years. Here we report a novel pathway to control HSCs by regulating glutamine metabolism. We demonstrated that the proliferation of HSCs is critically dependent on glutamine that is used to generate α-ketoglutarate (α-KG) and non-essential amino acid (NEAA). In addition, both culture- and in vivo-activated HSCs have increased glutamine utilization and increased expression of genes related to glutamine metabolism, including GLS (glutaminase), aspartate transaminase (GOT1) and glutamate dehydrogenase (GLUD1). Inhibition of these enzymes, as well as glutamine depletion, had a significant inhibitory effect on HSCs activation. In addition to providing energy expenditure, conversion of glutamine to proline is enhanced. The pool of free proline may also be increased via downregulation of POX expression. Hedgehog signaling plays an important role in the regulation of glutamine metabolism, as well as TGF-β1, c-Myc, and Ras signalings, via transcriptional upregulation and repression of key metabolic enzymes in this pathway. Finally, changes in glutamine metabolism were also found in mouse liver tissue following CCl4-induced acute injury.Glutamine metabolism plays an important role in regulating the proliferation and activation of HSCs. Strategies that are targeted at glutamine metabolism may represent a novel therapeutic approach to the treatment of liver fibrosis.

Mutations of acid sphingomyelinase (ASMase) cause Niemann-Pick diseases type A and B, which are fatal inherited lipid lysosomal storage diseases, characterized with visceral organ abnormalities and neurodegeneration. However, the effects of suppressing retinal ASMase expression are not understood. The goal of this study was to determine if the disruption of ASMase expression impacts the retinal structure and function in the mouse, and begin to investigate the mechanisms underlying these abnormalities.Acid sphingomyelinase knockout (ASMase KO) mice were utilized to study the roles of this sphingolipid metabolizing enzyme in the retina. Electroretinogram and morphometric analysis were used to assess the retinal function and structure at various ages. Sphingolipid profile was determined by liquid chromatography-mass spectrometry. Western blots evaluated the level of the autophagy marker LC3-II.When compared to control animals, ASMase KO mice exhibited significant age-dependent reduction in ERG a- and b-wave amplitudes. Associated with these functional deficits, morphometric analysis revealed progressive thinning of retinal layers; however, the most prominent degeneration was observed in the photoreceptor and outer nuclear layer. Additional analyses of ASMase KO mice revealed early reduction in ERG c-wave amplitudes and increased lipofuscin accumulation in the retinal pigment epithelium (RPE). Sphingolipid analyses showed abnormal accumulation of sphingomyelin and sphingosine in ASMase KO retinas. Western blot analyses showed a higher level of the autophagosome marker LC3-II.These studies demonstrate that ASMase is necessary for the maintenance of normal retinal structure and function. The early outer retinal dysfunction, outer segment degeneration, accumulation of lipofuscin and autophagosome markers provide evidence that disruption of lysosomal function contributes to the age-dependent retinal degeneration exhibited by ASMase KO mice.

Stem cell factor (SCF) can stimulate hematopoietic stem cell (HSC) expansion; however, the specific structural region(s) of SCF protein that are critical for this function are still unknown. A novel monoclonal antibody (named 23C8) against recombinant human SCF (rhSCF) was previously found to inhibit the ability of rhSCF to enhance HSC expansion, making it possible to identify the relevant active region to HSC.Eleven polypeptides were synthesized, which were designed to cover the full-length of rhSCF, with overlaps that are at least 3 amino acids long. ELISA was used to identify the polypeptide(s) that specifically react with the anti-SCF. The effects of the synthetic polypeptides on human HSC expansion, or on the ability of the full-length rhSCF to stimulate cell proliferation, were evaluated ex vivo. Total cell number was monitored using hemocytometer whereas CD34+ cell number was calculated based on the proportion determined via flow cytometry on day 6 of culture.Of all polypeptides analyzed, only one, named P0, corresponding to the SCF protein sequence at residues 39-56, was recognized by 23C8 mAb during ELISA. P0 stimulated the expansion of CD34+ cells derived from human umbilical cord blood (UCB). Addition of P0 increased the numbers of total mononucleated cells and CD34+ cells, by ~2 fold on day 6. P0 also showed partial competition against full-length rhSCF in the ex vivo cell expansion assay.Residues 39-56 of rhSCF comprise a critical functional region for its ability to enhance expansion of human UCB CD34+ cells. The peptide P0 is a potential candidate for further development as a synthetic substitute for rhSCF in laboratory and clinical applications.

Cassava polyploid breeding has drastically improved our knowledge on increasing root yield and its significant tolerance to stresses. In polyploid cassava plants, increases in DNA content highly affect cell volumes and anatomical structures. However, the mechanism of this effect is poorly understood. The purpose of the present study was to compare and validate the changes between cassava cultivar NZ199 diploid and autotetraploid at proteomic levels. The results showed that leaf proteome of cassava cultivar NZ199 diploid was clearly differentiated from its autotetraploid genotype using 2-DE combined MS technique. Sixty-five differential protein spots were seen in 2-DE image of autotetraploid genotype in comparison with that of diploid. Fifty-two proteins were identified by MALDI-TOF-MS/MS, of which 47 were up-regulated and 5 were down-regulated in autotetraploid genotype compared with diploid genotype. The classified functions of 32 up-regulated proteins were associated with photosynthesis, defense system, hydrocyanic acid (HCN) metabolism, protein biosynthesis, chaperones, amino acid metabolism and signal transduction. The remarkable variation in photosynthetic activity, HCN content and resistance to salt stress between diploid and autotetraploid genotypes is closely linked with expression levels of proteomic profiles. The analysis of protein interaction networks indicated there are direct interactions between the 15 up-regulation proteins involved in the pathways described above. This work provides an insight into understanding the protein regulation mechanism of cassava polyploid genotype, and gives a clue to improve cassava polyploidy breeding in increasing photosynthesis and resistance efficiencies.

Determining the generic delimitations within Aeridinae has been a significant issue in the taxonomy of Orchidaceae, and Holcoglossum is a typical case. We investigated the phylogenetic utility of the morphological traits of leaf epidermis in the taxonomy of Holcoglossum s.l. by using light and scanning electron microscopy to analyze 38 samples representing 12 species of Holcoglossum, with five species from five closely related genera, such as Ascocentrum, Luisia, Papilionanthe, Rhynchostylis and Vanda. Our results indicated that Holcoglossum can be distinguished from the related genera based on cuticular wax characteristics, and the inclusion of Holcoglossum himalaicum in Holcoglossum is supported by the epidermis characteristics found by LM and SEM. The percentage of the tetracytic, brachyparacytic, and laterocytic stomata types as well as the stomata index and certain combinations of special wax types support infrageneric clades and phylogenetic relationships that have been inferred from molecular data. Laterocytic and polarcytic stomata are perhaps ecological adaptations to the strong winds and ample rains in the alpine region of the Hengduanshan Mountains.

INTRODUCTION: Intra-abdominal hypertension (IAH) is known as a common, serious complication in critically ill patients. Bacterial translocation and permeability changes are considered the pathophysiological bases for IAH-induced enterogenic endotoxemia and subsequent multiorgan failure. Nevertheless, the effects of slightly elevated intra-abdominal pressures (IAPs) on the intestinal mucosa and the associated mechanisms remain unclear. METHODS: To investigate the acute effects of different nitrogen pneumoperitoneum grades on colonic mucosa, male Sprague-Dawley rats were assigned to six groups with different IAPs (0 [control], 4, 8, 12, 16, and 20 mmHg, n = 6/group). During 90 min of exposure, we dynamically monitored the heart rate and noninvasive hemodynamic parameters. After gradual decompression, arterial blood gas analyses were conducted. Thereafter, structural injuries to the colonic mucosa were identified using light microscopy. Colon permeability was determined using the expression of tight junction proteins, combined with fluorescein isothiocyanate dextran (FD-4) absorption. The pro-oxidant-antioxidant balance was determined based on the levels of malondialdehyde (MDA) and antioxidant enzymes. RESULTS: IAH significantly affected the histological scores of the colonic mucosa, tight junction protein expression, mucosal permeability, and pro-oxidant-antioxidant balance. Interestingly, elevations of IAP that were lower than the threshold for IAH also showed a similar, undesirable effect. In the 8 mmHg group, mild hyponatremia, hypocalcemia, and hypoxemia occurred, accompanied by reduced blood and abdominal perfusion pressures. Mild microscopic inflammatory infiltration and increased MDA levels were also detected. Moreover, an 8-mm Hg IAP markedly inhibited the expression of tight junction proteins, although no significant differences in FD-4 permeability were observed between the 0- and 8-mmHg groups. CONCLUSIONS: Acute exposure to slightly elevated IAP may result in adverse effects on intestinal permeability and the pro-oxidant-antioxidant balance. Therefore, in patients with critical illnesses, IAP should be dynamically monitored and corrected, as soon as possible, to prevent intestinal mucosal injury and subsequent gut-derived sepsis.

Regulator of Cullins-1 (ROC1) is a key subunit in the Cullin-RING ligase (CRL) protein complex. Overexpression of ROC1 protein is associated with tumor progression and poor prognosis of non-muscle invasive bladder transitional cell carcinoma (NMIBC). This study was designed to assess the effects of ROC1 knockdown in bladder cancer cells and to determine the potential mechanisms involved. A total of 112 bladder cancer tissue specimens were recruited for immunohistochemical analyses of ROC1 overexpression. Bladder cancer cell lines were used to knockdown ROC1 expression using ROC1 siRNA. Our data showed that ROC1 knockdown remarkably inhibited bladder cancer cell growth, arrested cells at the G2 phase of the cell cycle, and induced the p53-dependent cell senescence. Molecularly, G2 arrest was associated with upregulation of p21, p27, cyclin B1, and Cdc2 proteins. ROC1 knockdown induced-senescence functioned through p53/p21 pathway. Knockdown of p21 expression partially rescued ROC1 knockdown-induced growth inhibition in cancer cells. Furthermore, nude mouse xenograft analyses confirmed these in vitro data. In conclusion, data from the current study indicate that ROC1 plays an essential role in bladder cancer progression and could serve as a novel anticancer target for bladder transitional cell carcinoma (BTCC).

CD73 functions as an ecto-5'-nucleotidase to produce extracellular adenosine that has anti-inflammatory and immunosuppressive activity. We here demonstrate that CD73 helps control graft-versus-host disease (GVHD) in mouse models. Survival of wild-type (WT) recipients of either allogeneic donor naïve CD73 knock-out (KO) or WT T cells was similar suggesting that donor naïve T cell CD73 did not contribute to GVHD. By contrast, donor CD73 KO CD4(+)CD25(+) regulatory T cells (Treg) had significantly impaired ability to mitigate GVHD mortality compared to WT Treg, suggesting that CD73 on Treg is critical for GVHD protection. However, compared to donor CD73, recipient CD73 is more effective in limiting GVHD. Pharmacological blockade of A2A receptor exacerbated GVHD in WT recipients, but not in CD73 KO recipients, suggesting that A2 receptor signaling is primarily implicated in CD73-mediated GVHD protection. Moreover, pharmacological blockade of CD73 enzymatic activity induced stronger alloreactive T cell activity, worsened GVHD and enhanced the graft-versus-leukemia (GVL) effect. These findings suggest that both donor and recipient CD73 protects against GVHD but also limits GVL effects. Thus, either enhancing or blocking CD73 activity has great potential clinical application in allogeneic bone marrow transplants.

Parathyroid hormone (PTH) is a potent anabolic agent for the treatment of osteoporosis. However, its mechanism of action in osteoblast and bone is not well understood. In this study, we show that the anabolic actions of PTH in bone are severely impaired in both growing and adult ovariectomized mice lacking bone-related activating transcription factor 4 (ATF4). Our study demonstrates that ATF4 deficiency suppresses PTH-stimulated osteoblast proliferation and survival and abolishes PTH-induced osteoblast differentiation, which, together, compromise the anabolic response. We further demonstrate that the PTH-dependent increase in osteoblast differentiation is correlated with ATF4-dependent up-regulation of Osterix. This regulation involves interactions of ATF4 with a specific enhancer sequence in the Osterix promoter. Furthermore, actions of PTH on Osterix require this same element and are associated with increased binding of ATF4 to chromatin. Taken together these experiments establish a fundamental role for ATF4 in the anabolic actions of PTH on the skeleton.

The coal mining might cause the disturbance to the vegetation and the disturbance impacts might exist the differences for different areas, and few literatures compared and analyzed different disturbed areas based on the location of the mining face, and paid attention to the post mining self-healing effects of vegetation. Here, this paper selected the GaoFen multispectral images during 2017-2021 to study different areas of Shangwan Mine which includes the old mining area more than 5 years after mining, the new working face underground mined in 2018 and 2019, the natural growth control area and the open-pit mining affected area. The spatiotemporal changes of the surface fraction vegetation coverage (FVC) were analyzed in each area and the correlation between vegetation coverage and climatic factors was studied. The results showed that: (1) The overall vegetation coverage showed a moderate decrease trend in fluctuation from 2017 to 2021. The Open-pit mining affected areas showed the largest decline, reaching 68.3%. The FVC in the underground mining areas had a downward trend, but self-healing effect after mining was also observed. (2) The overall FVC in the study area was positively correlated with the number of precipitation days. (3) There were differences in the sensitivity to mining disturbance for different landform in the underground mining areas. (4) Although the FVC in the Old mining areas had recovered to the level of Natural growth control area, but the annual fluctuation was larger, which might mean lower ecological stability.

Improving the job satisfaction of vocational education teachers (VET) is necessary for maintaining the stability of the vocational education teaching force and is an essential support for enhancing the professional attractiveness and ensuring the quality of VET. Unlike previous studies, firstly, in terms of groups, the particular group of teachers in this study focuses on VET, which in reality is often overlooked compared to other groups of teachers due to the low level of recognition of vocational education (VE) in China. Secondly, this phenomenon is more prominent and less researched regionally in economically underdeveloped areas due to the uneven and disparate economic development between the East and West of China. In terms of sample size, previous studies have lacked large samples, making it difficult to obtain convincing and realistic results. Finally, most previous studies considered teachers' job satisfaction (TJS) in terms of external or internal factors alone. However, this study considers a combination of the external factor of the school climate (SC) in which VET works and the internal factor of teachers' self-efficacy (TSE) to explore the relationship with TJS and its impact. Based on data from a survey of 1035 teachers in China, a structural equation model estimation method was used to explore and analyze the impact of SC and TSE on their TJS and the specific role of the relationship. The research found that VET-perceived SC is positively predicting TJS; VET-perceived SC is positively predicting TSE; TSE is positively predicting TJS; TSE significantly mediates the relationship between SC and TJS. This study provides a theoretical perspective that integrates the external organizational influences of SC and introduces the internal psychological factor of TSE as a mediating variable to understand TJS. In practice, it helps raise the importance of VET and provides empirical data and intellectual support to the relevant government departments in improving TJS.

As a branch of the two-dimensional (2D) optimal blanking problem, rectangular strip packing is a typical non-deterministic polynomial (NP-hard) problem. The classical packing solution method relies on heuristic and metaheuristic algorithms. Usually, it needs to be designed with manual decisions to guide the solution, resulting in a small solution scale, weak generalization, and low solution efficiency. Inspired by deep learning and reinforcement learning, combined with the characteristics of rectangular piece packing, a novel algorithm based on deep reinforcement learning is proposed in this work to solve the rectangular strip packing problem. The pointer network with an encoder and decoder structure is taken as the basic network for the deep reinforcement learning algorithm. A model-free reinforcement learning algorithm is designed to train network parameters to optimize the packing sequence. This design can not only avoid designing heuristic rules separately for different problems but also use the deep networks with self-learning characteristics to solve different instances more widely. At the same time, a piece positioning algorithm based on the maximum rectangles bottom-left (Maxrects-BL) is designed to determine the placement position of pieces on the plate and calculate model rewards and packing parameters. Finally, instances are used to analyze the optimization effect of the algorithm. The experimental results show that the proposed algorithm can produce three better and five comparable results compared with some classical heuristic algorithms. In addition, the calculation time of the proposed algorithm is less than 1 second in all test instances, which shows a good generalization, solution efficiency, and practical application potential.

The Harris hawks optimization (HHO) algorithm is a new swarm-based natural heuristic algorithm that has previously shown excellent performance. However, HHO still has some shortcomings, which are premature convergence and falling into local optima due to an imbalance of the exploration and exploitation capabilities. To overcome these shortcomings, a new HHO variant algorithm based on a chaotic sequence and an opposite elite learning mechanism (HHO-CS-OELM) is proposed in this paper. The chaotic sequence can improve the global search ability of the HHO algorithm due to enhancing the diversity of the population, and the opposite elite learning can enhance the local search ability of the HHO algorithm by maintaining the optimal individual. Meanwhile, it also overcomes the shortcoming that the exploration cannot be carried out at the late iteration in the HHO algorithm and balances the exploration and exploitation capabilities of the HHO algorithm. The performance of the HHO-CS-OELM algorithm is verified by comparison with 14 optimization algorithms on 23 benchmark functions and an engineering problem. Experimental results show that the HHO-CS-OELM algorithm performs better than the state-of-the-art swarm intelligence optimization algorithms.

Previous experimental studies have regarded distraction, an emotional regulation strategy, as an attentional disengagement strategy and considered it to be maladaptive in the long term. This study intends to further examine the relationship between distraction and negative emotions by using a questionnaire and a multiple mediation model. A total of 723 college students completed the distraction, cognitive reappraisal and problem-solving subscales of the Measurement of Affect Regulation Styles, the Needs Satisfaction Questionnaire, the Meaningful Life Measure, and the Emotional Experience Questionnaire of Well-being. Structural equation modeling (SEM) was performed, and mediation effects were tested. The results showed that (1) distraction was used significantly more frequently than problem-solving and cognitive reappraisal, with a large effect size (partial η2 = 0.321 > 0.138), and (2) distraction had an effect on negative emotions through two multiple mediation paths, i.e., positive emotion-cognitive reappraisal-meaning in life, and positive emotion-problem-solving-needs satisfaction. Distraction reduces negative emotions by enhancing positive emotions and facilitating cognitive reappraisal, problem-solving, meaning in life and needs satisfaction. It is not a kind of avoidance but a temporary rest to strive for a better life.

Recent emerging data indicate that the increase in the expression and activity of the transforming growth factor beta 1 (Tgf-β1) signaling may have detrimental effect to mature articular cartilage of knee joints. However, there is no information about whether or not this is the case in condylar cartilages. The objective of this study is to investigate the protein expression and activity of Tgf-β1 signaling in degenerative condylar cartilages. We also investigate biological effects of the conditional deletion of transforming growth factor receptor type II (Tgfbr2) in condylar cartilage of adult mice after a partial discectomy. Two mouse models of osteoarthritis (OA) were used to examine protein expressions of Tgf-β1 and p-Smad2/3 in condylar cartilages at early degenerative stages. In addition, cartilage specific Tgfbr2-deficient adult mice were subjected to a partial discectomy. The morphological condition of condylar cartilages was evaluated in mice at 4 and 12 weeks after the surgery. We found that protein levels of Tgf-β1 and p-Smad2/3 were increased in the degenerative condylar cartilage of the mouse models. The conditional removal of Tgfbr2 in mature condylar cartilage significantly delayed the progressive progression of the cartilage degeneration induced by a partial discectomy. We conclude that the increase in the expression and activity of Tgf-β1 signaling may have detrimental effect to mature condylar cartilages. Therefore, inhibition of Tgf-β1 signaling may be able to protect condylar cartilages from being degraded in mature temporomandibular joints.

It has been identified that a TEV protease (TEVp) variant, TEVp(5M), displays improved solubility. Here, we constructed fifteen TEVp(5M) variants with one or more of six rare arginine codons in the coding sequence replaced with abundant E. coli arginine codons. These codon variants expressed in either E. coli BL21 (DE3) or Rossetta (DE3) showed different solubility and activity. Supply of rare tRNAs increased the tendency of certain codon variants to form insoluble aggregates at early induction stage, as determined by the fused S-tag. About 32% increase in soluble protein production of M5 variant with four synonymously mutated arginine codons was identified in Rossetta (DE3) cells using GFP fusion reporter, comparable to that of TEVp(5M). After purification, two other codon variants from both E. coli strains exhibited less activity than TEVp(5M) on cleaving the native or modified recognition sequence incorporated between GST and E. coli diaminopropionate ammonialyase by enzyme-coupled assay, whereas purified M5 variant showed activity similar to the TEVp(5M). Supply of rare tRNAs caused the decrease of activity of TEVp(5M) and M5 by about 21%. Our results revealed that engineering of highly soluble TEVp variants can be achieved by the combined mutations of amino acid residues and optimization of specific rare codons, whereas simple augment of rare tRNAs abundance resulted in partial loss of activity.

Regeneration of auditory hair cells (HCs) is a promising approach to restore hearing. Recent studies have demonstrated that induced pluripotent stem cells/embryonic stem cells or supporting cells (SCs) adjacent to HCs can be converted to adopt the HC fate. However, little is known about whether new HCs are characteristic of outer or inner HCs. Here, we showed in vivo conversion of 2 subtypes of SCs, inner border cells (IBs) and inner phalangeal cells (IPhs), to the inner HC (IHC) fate. This was achieved by ectopically activating Atoh1, a transcription factor necessary for HC fate, in IBs/IPhs at birth. Atoh1+ IBs/IPhs first turned on Pou4f3, another HC transcription factor, before expressing 8 HC markers. The conversion rate gradually increased from ∼ 2.4% at 1 week of age to ∼ 17.8% in adult. Interestingly, new HCs exhibited IHC characteristics such as straight line-shaped stereociliary bundles, expression of Fgf8 and otoferlin, and presence of larger outward currents than those of outer HCs. However, new HCs lacked the terminal differentiation IHC marker vGlut3, exhibited reduced density of presynaptic Cbtp2 puncta that had little postsynaptic GluR2 specialization, and displayed immature IHC outward currents. Our results demonstrate that the conversion rate of IBs/IPhs in vivo by Atoh1 ectopic expression into the IHC fate was higher and faster and the conversion was more complete than that of the 2 other SC subtypes underneath the outer HCs; however, these new IHCs are arrested before terminal differentiation. Thus, IBs/IPhs are good candidates to regenerate IHCs in vivo.

Various cochlear pathologies, such as acoustic trauma, ototoxicity and age-related degeneration, cause hearing loss. These pre-existing hearing losses can alter cochlear responses to subsequent acoustic overstimulation. So far, the knowledge on the impacts of pre-existing hearing loss caused by genetic alteration of cochlear genes is limited. Prestin is the motor protein expressed exclusively in outer hair cells in the mammalian cochlea. This motor protein contributes to outer hair cell motility. At present, it is not clear how the interference of prestin function affects cochlear responses to acoustic overstimulation. To address this question, a genetic model of prestin dysfunction in mice was created by inserting an internal ribosome entry site (IRES)-CreERT2-FRT-Neo-FRT cassette into the prestin locus after the stop codon. Homozygous mice exhibit a threshold elevation of auditory brainstem responses with large individual variation. These mice also display a threshold elevation and a shift of the input/output function of the distortion product otoacoustic emission, suggesting a reduction in outer hair cell function. The disruption of prestin function reduces the threshold shifts caused by exposure to a loud noise at 120 dB (sound pressure level) for 1 h. This reduction is positively correlated with the level of pre-noise cochlear dysfunction and is accompanied by a reduced change in Cdh1 expression, suggesting a reduction in molecular responses to the acoustic overstimulation. Together, these results suggest that prestin interference reduces cochlear stress responses to acoustic overstimulation.

We have shown that angiotensin II (Ang II) and angiotensin-(1-7) [Ang-(1-7)] increased arterial blood pressure (BP) via glutamate release when microinjected into the rostral ventrolateral medulla (RVLM) in normotensive rats (control). In the present study, we tested the hypothesis that Ang II and Ang-(1-7) in the RVLM are differentially activated in stress-induced hypertension (SIH) by comparing the effects of microinjection of Ang II, Ang-(1-7), and their receptor antagonists on BP and amino acid release in SIH and control rats. We found that Ang II had greater pressor effect, and more excitatory (glutamate) and less inhibitory (taurine and γ-aminobutyric acid) amino acid release in SIH than in control animals. Losartan, a selective AT₁ receptor (AT₁R) antagonist, decreased mean BP in SIH but not in control rats. PD123319, a selective AT₂ receptor (AT₂R) antagonist, increased mean BP in control but not in SIH rats. However, Ang-(1-7) and its selective Mas receptor antagonist Ang779 evoked similar effects on BP and amino acid release in both SIH and control rats. Furthermore, we found that in the RVLM, AT₁R, ACE protein expression (western blot) and ACE mRNA (real-time PCR) were significantly higher, whereas AT₂R protein, ACE2 mRNA and protein expression were significantly lower in SIH than in control rats. Mas receptor expression was similar in the two groups. The results support our hypothesis and demonstrate that upregulation of Ang II by AT₁R, not Ang-(1-7), system in the RVLM causes hypertension in SIH rats by increasing excitatory and suppressing inhibitory amino acid release.

OBJECTIVE: The rapid progress in fetal echocardiography has lead to early detection of congenital heart diseases. Increasing evidences have shown that prenatal diagnosis could be life saving in certain cases. However, there is no agreement on which protocol is most adaptive diagnostic one. Thus, we use meta-analysis to conduct a pooled performance test on 5 diagnostic protocols. METHODS: We searched PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials and WHO clinical trails registry center to identify relevant studies up to August, 2012. We performed meta-analysis in a fixed/random-effect model using Meta-disc 1.4. We used STATA 11.0 to estimate the publication bias and SPSS 17.0 to evaluate variance. RESULTS: We use results from 81 studies in 63 articles to analyze the pooled accuracy. The overall performance of pooled sensitivities of spatiotemporal image correlation (STIC), extend cardiac echography examination (ECEE) and 4 chambers view + outflow tract view + 3 vessels and trachea view (4 CV+OTV+3 VTV) were around 0.90, which was significant higher than that of 4 chambers view + outflow tract view or 3 vessels and trachea view (4 CV+OTV/3 VTV) and 4 chambers view (4 CV). Unfortunately the pooled specificity of STIC was 0.92, which was significant lower than that of other 4 protocols which reached at 1.00. The area under the summary receiver operating characteristic curves value of STIC, ECEE, 4 CV+OTV+3 VTV, 4 CV+OTV/3 VTV and 4 CV were 0.9700, 0.9971, 0.9983, 0.9929 and 0.9928 respectively. CONCLUSION: These results suggest a great diagnostic potential for fetal echocardiography detection as a reliable method of fetal congenital heart disease. But at least 3 sections view (4 CV, OTV and 3 VTV) should be included in scan protocol, while the STIC can be used to provide more information for local details of defects, and can not be used to make a definite diagnosis alone with its low specificity.

The mammalian outer hair cells (OHCs) provide a positive mechanical feedback to enhance the cochlea's hearing sensitivity and frequency selectivity. Although the OHC-specific, somatic motor protein prestin is required for cochlear amplification, it remains unclear whether prestin can provide sufficient cycle-by-cycle feedback. In cochlear mechanical modeling, varying amounts of OHC motor activity should provide varying degrees of feedback efficiency to adjust the gain of cochlear amplifier at resonant frequencies. Here we created and characterized two new prestin-hypomorphic mouse models with reduced levels of wild-type prestin. OHCs from these mice exhibited length, total elementary charge movement (Q(max)), charge density, and electromotility intermediate between those of wild-type and prestin-null mice. Remarkably, measurements of auditory brainstem responses and distortion product otoacoustic emissions from these mice displayed wild-type like hearing sensitivities at 4-22 kHz. These results indicate that as low as 26.7% Q(max), 34.0% charge density and 44.0% electromotility in OHCs were sufficient for wild-type-like hearing sensitivity in mice at 4-22 kHz, and that these in vitro parameters of OHCs did not correlate linearly with the feedback efficiency for in vivo gain of the cochlear amplifier. Our results thus provide valuable data for modeling cochlear mechanics and will stimulate further mechanistic analysis of the cochlear amplifier.

During mouse inner ear development, Notch1 signaling first specifies sensory progenitors, and subsequently controls progenitors to further differentiate into either hair cells (HCs) or supporting cells (SCs). Overactivation of NICD (Notch1 intracellular domain) at early embryonic stages leads to ectopic HC formation. However, it remains unclear whether such an effect can be elicited at later embryonic or postnatal stages, which has important implications in mouse HC regeneration by reactivation of Notch1 signaling.We performed comprehensive in vivo inducible overactivation of NICD at various developmental stages. In CAG(CreER+); Rosa26-NICD(loxp/+) mice, tamoxifen treatment at embryonic day 10.5 (E10.5) generated ectopic HCs in the non-sensory regions in both utricle and cochlea, whereas ectopic HCs only appeared in the utricle when tamoxifen was given at E13. When tamoxifen was injected at postnatal day 0 (P0) and P1, no ectopic HCs were observed in either utricle or cochlea. Interestingly, Notch1 signaling induced new HCs in a non-cell-autonomous manner, because the new HCs did not express NICD. Adjacent to the new HCs were cells expressing the SC marker Sox10 (either NICD+ or NICD-negative).Our data demonstrate that the developmental stage determines responsiveness of embryonic otic precursors and neonatal non-sensory epithelial cells to NICD overactivation, and that Notch 1 signaling in the wild type, postnatal inner ear is not sufficient for generating new HCs. Thus, our genetic mouse model is suitable to test additional pathways that could synergistically interact with Notch1 pathway to produce HCs at postnatal ages.

The recent development of a Hepatitis C virus (HCV) infectious virus cell culture model system has facilitated the development of whole-virus screening assays which can be used to interrogate the entire virus life cycle. Here, we describe the development of an HCV growth assay capable of identifying inhibitors against all stages of the virus life cycle with assay throughput suitable for rapid screening of large-scale chemical libraries. Novel features include, 1) the use of an efficiently-spreading, full-length, intergenotypic chimeric reporter virus with genotype 1 structural proteins, 2) a homogenous assay format compatible with miniaturization and automated liquid-handling, and 3) flexible assay end-points using either chemiluminescence (high-throughput screening) or Cellomics ArrayScan™ technology (high-content screening). The assay was validated using known HCV antivirals and through a large-scale, high-throughput screening campaign that identified novel and selective entry, replication and late-stage inhibitors. Selection and characterization of resistant viruses provided information regarding inhibitor target and mechanism. Leveraging results from this robust whole-virus assay represents a critical first step towards identifying inhibitors of novel targets to broaden the spectrum of antivirals for the treatment of HCV.

Streptococcussuis serotype 2 (SS 2) is an important zoonotic pathogen that has caused two major infectious outbreaks of streptococcal toxic shock syndrome (STSS) in China. A novel gene located in the 89K pathogenicity island (PAI) encoding a putative hemolysin-III-related protein (Hhly3) has been previously characterized. In this study, the SS2 deletion mutant of the exogenous gene hhly3 was constructed by homologous recombination. This protein was found to exhibit cytolytic activity, and hemolytic activity of the hhly3 gene knockout mutant (Δhhly3) was significantly lower than that in the wild-type strain ZY05719. In addition, qRT-PCR revealed that Hhly3 played an important role in the expression of the secreted hemolysin SLY, which may be the key reason for the decreased hemolytic activity. Consequently, compared with the WT strain, the infection and pathogenicity of Δhhly3 was also decreased, as evidenced by in vitro bacterial growth in whole blood and by the in vivo zebrafish test, suggesting that hhly3 is a novel exogenous hemolysis-related gene in SS2 strains.