What Contributes to the MIC? Beyond ß-Lactamase Gene Detection in Klebsiella pneumoniae.

BACKGROUND: K. pneumoniae is capable of resistance to ß-lactam antibiotics through expression of ß-lactamases (both chromosomal and plasmid-encoded) and downregulation of outer membrane porins. However, the extent to which these mechanisms interplay in a resistant phenotype is not well understood. The purpose of this study was to determine the extent to which ß-lactamases and outer membrane porins affected ß-lactam resistance. METHODS: MICs to ß-lactams and inhibitor combinations were determined by agar dilution or E-test. Outer membrane porin production was evaluated by western blot of outer membrane fractions. ß-lactamase carriage was determined by whole genome sequencing and expression evaluated by RT-qPCR. RESULTS: Plasmid-encoded ß--lactamases were important for cefotaxime and ceftazidime resistance. Elevated expression of chromosomal SHV was important for ceftolozane/tazobactam resistance. Loss of outer membrane porins was predictive of meropenem resistance. ESßLs and pAmpCs in addition to porin loss were sufficient to confer resistance to the third generation cephalosporins, pipercillin/tazobactam, ceftolozane/tazobactam, and meropenem. pAmpCs (CMY-2 and DHA) alone conferred resistance to pipercillin/tazobactam. DISCUSSION: Detection of a resistance gene by whole genome sequencing was not sufficient to predict resistance to all antibiotics tested. some ß-lactam resistance was dependent on the expression of both plasmid-encoded and chromosomal ß-lactamases and loss of porins.

Vitamin C, vitamin E, ß-carotene and risk of Parkinson's disease: a systematic review and dose-response meta-analysis of observational studies.

OBJECTIVE: This study aimed to explore the relationship between the intake of vitamin C, vitamin E and ß-carotene, and the risk of Parkinson's disease (PD). METHODS: Web of Science, Embase, PubMed, Cochrane library, CNKI, and WanFang databases were searched from inception to 29 August 2022 for observational studies reporting the odds ratios (ORs) or relative risks (RRs) or hazard ratios (HRs) and 95% confidence intervals (CIs) of PD by Vitamin C/Vitamin E/ß-carotene intake. Random-effects models, publication bias assessment, subgroup, sensitivity and dose-response analyses were performed, using.Stata version 12.0. RESULTS: A total of 13 studies were included. There was no significant association between high-dose vitamin C intake and the risk of PD compared with low-dose vitamin C intake (RR = 0.98, 95%CI:0.89,1.08). Compared with low-dose intake, high-dose intake of vitamin E can prevent the risk of PD (RR = 0.87, 95%CI:0.77,0.99). Compared with lower ß-carotene intake, there was a borderline non-significant correlation between higher intake and PD risk (RR = 0.91, 95%CI:0.82,1.01), and high dose ß-carotene intake was found to be associated with a lower risk of PD in women (RR = 0.78, 95%CI:0.64,0.96). CONCLUSION: This study shows that vitamin E intake can reduce the risk of PD and play a preventive role.

Impact of sex on in-hospital mortality and 90-day readmissions in patients undergoing transcatheter mitral valve replacement (TMVR): Analysis from the nationwide readmission database.

OBJECTIVES: To evaluate sex differences in in-hospital mortality and 90-day readmission rates among patients undergoing transcatheter mitral valve replacement (TMVR) in the United States of America. BACKGROUND: Women have higher rates of mortality and rehospitalization than men following many cardiac procedures. TMVR has grown as an alternative to mitral valve surgery for patients at high surgical risk. The rates of TMVR mortality and rehospitalization by sex are unknown. METHODS: We analyzed the Nationwide Readmissions Database (NRD) from 2016 to 2019 to identify hospitalizations for TMVR. Sex differences in in-hospital mortality and 90-day readmissions were determined using logistic regression models. RESULTS: Between 2016 and 2019, 4109 hospitalizations for TMVR were identified, comprised of 1758 (42.8%) men and 2351 (57.2%) women. The median age was 74 years for both men and women. There was no significant difference in in-hospital mortality during index hospitalization (6.51% vs. 6.69%; p = 0.852) and all-cause 90-day readmission (28.19% vs. 29.59%; p = 0.563) between men and women. Across the study period, trend analysis did not reveal a significant change in in-hospital mortality (men p = 0.087, women p = 0.194) or 90-day readmission rates (men p = 0.569, women p = 0.454). CONCLUSIONS: In patients undergoing TMVR, in-hospital mortality and 90-day readmissions are similar between men and women. Between 2016 and 2019, TMVR in-hospital mortality and 90-day readmission rates remained unchanged. Further research is necessary to confirm these findings.

HIV-1 Tat-mediated astrocytic amyloidosis involves the HIF-1α/lncRNA BACE1-AS axis.

Increased life expectancy of patients diagnosed with HIV in the current era of antiretroviral therapy is unfortunately accompanied with the prevalence of HIV-associated neurocognitive disorders (HANDs) and risk of comorbidities such as Alzheimer-like pathology. HIV-1 transactivator of transcription (Tat) protein has been shown to induce the production of toxic neuronal amyloid protein and also enhance neurotoxicity. The contribution of astrocytes in Tat-mediated amyloidosis remains an enigma. We report here, in simian immunodeficiency virus (SIV)+ rhesus macaques and patients diagnosed with HIV, brain region-specific up-regulation of amyloid precursor protein (APP) and Aß (40 and 42) in astrocytes. In addition, we find increased expression of ß-site cleaving enzyme (BACE1), APP, and Aß in human primary astrocytes (HPAs) exposed to Tat. Mechanisms involved up-regulation of hypoxia-inducible factor (HIF-1α), its translocation and binding to the long noncoding RNA (lncRNA) BACE1-antisense transcript (BACE1-AS), resulting, in turn, in the formation of the BACE1-AS/BACE1 RNA complex, subsequently leading to increased BACE1 protein, and activity and generation of Aß-42. Gene silencing approaches confirmed the regulatory role of HIF-1α in BACE1-AS/BACE1 in Tat-mediated amyloidosis. This is the first report implicating the role of the HIF-1α/lncRNABACE1-AS/BACE1 axis in Tat-mediated induction of astrocytic amyloidosis, which could be targeted as adjunctive therapies for HAND-associated Alzheimer-like comorbidity.

Exploring causal mechanisms and quantifying direct and indirect effects using a joint modeling approach for recurrent and terminal events.

Recurrent events are commonly encountered in biomedical studies. In many situations, there exist terminal events, such as death, which are potentially related to the recurrent events. Joint models of recurrent and terminal events have been proposed to address the correlation between recurrent events and terminal events. However, there is a dearth of suitable methods to rigorously investigate the causal mechanisms between specific exposures, recurrent events, and terminal events. For example, it is of interest to know how much of the total effect of the primary exposure of interest on the terminal event is through the recurrent events, and whether preventing recurrent event occurrences could lead to better overall survival. In this work, we propose a formal causal mediation analysis method to compute the natural direct and indirect effects. A novel joint modeling approach is used to take the recurrent event process as the mediator and the survival endpoint as the outcome. This new joint modeling approach allows us to relax the commonly used "sequential ignorability" assumption. Simulation studies show that our new model has good finite sample performance in estimating both model parameters and mediation effects. We apply our method to an AIDS study to evaluate how much of the comparative effectiveness of the two treatments and the effect of CD4 counts on the overall survival are mediated by recurrent opportunistic infections.

Mid-term Outcomes of Endovascular and Hybrid Procedures to Treat Complex Aortic Arch Pathologies.

PURPOSE: To compare the mid-term outcomes of endovascular and hybrid procedures in treating aortic arch pathologies with an unfavorable proximal landing zone, and analyze the different indications of the 2 methods. METHODS: We collected the clinical data from 59 patients with complex aortic arch pathologies who underwent endovascular or hybrid surgery from March 2018 to April 2020 at a single center. Among the patients, 45 were treated by branched or fenestrated surgery and 14 by hybrid surgery. The clinical data of preoperative, perioperative, and postoperative results were retrospectively analyzed and compared. The main study indexes were the branch patency rate and endoleakage rate during the follow-up period. The secondary study indexes included the operation success rate, operative time, hospital expenses, complication incidence, freedom from reintervention rate, mortality, etc. RESULTS: The operation success rate of all the groups was 100%. The hospital expenses of the hybrid group were lower than those of the endovascular group (p<0.05). The operative time of the hybrid group was longer than that of the endovascular group (p<0.05). The incidence of anatomic variants in the hybrid group was 28.6%, which was significantly higher than that in the endovascular group (2.2%, p=0.011). However, there were no significant differences in operative bleeding, ventilator use duration, and treatment time in intensive care units between the 2 groups (p>0.05). Follow-up was conducted for a period of 12 to 34 months. Four patients of the hybrid group experienced numbness of the upper limb (28.57%); the proportion was higher than the endovascular group (0%, p=0.002). There were no significant differences in the occurrence of endoleaks, retrograde aortic dissection, target lesion, secondary operation, branch patency rate, paraplegia, cerebral apoplexy, renal failure, or other complications in either group (p>0.05). The mortality of the endovascular group was 6.67% (3/45). Overall cumulative survival at 1 year was 100% in the hybrid group and 93.3% in the endovascular group. There was no statistical difference in the increase of the true lumen between the 2 groups for vascular remodeling (p>0.05). CONCLUSION: The hybrid surgery costs less and proves more suitable for treating variants of the aortic arch. The endovascular treatment still has limitations due to anatomical conditions.

Fibrin Glue Sac Filling for Preventing Type II Endoleak, Short-Term Outcomes of a Prospective Randomized Controlled Trial.

OBJECTIVE: Type II endoleak (T2EL) worsens the long-term results of endovascular aneurysm repair (EVAR). How to prevent T2ELs remains controversial. This study aimed to evaluate the efficacy and safety of fibrin glue sac filling (FGSF) to prevent T2ELs after EVAR. METHODS: A prospective randomized controlled trial was conducted. Patients were randomly divided into group A (standard EVAR + FGSF) and group B (standard EVAR). The follow-up plans included outpatient or telephone consultation at 1 and 3 months and computed tomography (CT) angiography at 6 months, 1 year, and once a year after EVAR. RESULTS: A total of 64 abdominal aortic aneurysm (AAA) patients were randomized to the 2 groups. All patients were followed up for more than 6 months. The 2 groups showed similar baseline characteristics. The rate of T2ELs on immediate angiography in group A (9.6%) was significantly lower than that in group B (33.3%, p=0.033). Moreover, the sac area change was significantly reduced in group A at 6 months after EVAR (p=0.021). However, T2EL incidence was similar at the 6-month (p=0.055) and 1-year (p=0.057) follow-ups, and AAA diameter change was also similar at 1 year. There were similar operation times, radiation doses, severe adverse events (SAEs), and reinterventions between the 2 groups. CONCLUSION: Fibrin glue sac filling could prevent short-term type II endoleaks and promote AAA shrinkage after 6 months. The FGSF procedure is swift and straightforward; however, patients are at risk of bowel ischemia, especially after previous bowel resections or concomitant superior mesenteric artery (SMA) disease. CLINICAL IMPACT: Standard endovascular aneurysm repair (EVAR) couldn't prevent type II endoleak (T2EL). In this study, we found fibrin glue sac filling (FGSF) could prevent T2EL and promote AAA shrinkage in a short term. And the FGSF procedure is easy, it will be a useful supplement to standard EVAR for clinicians. And FGSF might have potential usefulness on ruptured aneurysms, although without direct evidence.Fibrin glue is often used to hemostasis and tissue adhesion in surgical patients and burn patients, we firstly carry out a randomized controlled study and prove that fibrin glue sac filling could prevent T2EL and promote sac remodeling.

Outcomes of weight-based vs. fixed dose of Pembrolizumab among patients with non-small cell lung cancer.

OBJECTIVE: This study aims to assess outcomes among patients with non-small cell lung cancer (NSCLC) who received treatment with pembrolizumab on a weight-based dose (WBD) or fixed-dose (FD) regimen using a non-inferiority (NI) analysis. MATERIAL AND METHODS: This retrospective cohort study included adult patients with NSCLC weighing under 100 kg who received pembrolizumab between 1 January 2015 and 31 December 2020. Patients were grouped into either WBD or FD cohort based on the initial pembrolizumab dose and dosing regimen. The primary effectiveness outcome was overall survival (OS), analyzed using NI analysis with a lower margin of 10% comparing WBD to FD. Safety outcomes were all-cause emergency room visits or hospitalizations and incidence of selected immune-related adverse events (irAEs) and analyzed using NI analysis with an upper margin of 10%. All patients were followed until the end of health plan membership, death, or 30 June 2022, whichever occurred first. RESULTS: A total of 1413 patients were evaluated. OS was observed in 36.6% of the FD group, and 37.7% in the WBD group (rate difference: 1%, 90% CI: -6%-8%, NI p-value < 0.01). NI was met in all three safety outcomes: proportion of all-cause emergency room visits (rate difference: 1.1%, NI p-value < 0.01); proportion of hospitalizations (rate difference: 2%, NI p-value < 0.01); and composite incidence of irAEs (rate difference: -2.2%, NI p-value = 0.03). CONCLUSION: These findings suggest that WBD of pembrolizumab may be as appropriate as FD for the treatment of lung cancer.

Evaluation of the Effectiveness and Safety of Direct Oral Anticoagulants in Elderly Patients With Nonvalvular Atrial Fibrillation Who Are Not Candidates for Warfarin in Real-World Setting.

ABSTRACT: Limited literature has established the role of direct oral anticoagulants (DOAC) for elderly patients with nonvalvular atrial fibrillation who are unsuited for warfarin. Therefore, the objectives of this study were to assess the effectiveness and safety of DOAC use in this vulnerable patient population. This was a retrospective propensity score matching cohort study. Among all patients aged 75+ years who were not candidates for warfarin, we matched those who initiated DOAC between September 2017 and September 2018 with those who did not receive DOAC or warfarin in a 1:1 ratio. Effectiveness outcome was a composite measure of stroke, transient ischemic attack, and pulmonary embolism. Safety outcome was a composite measure of non-trauma-related intracranial hemorrhage and gastrointestinal bleed. Unless patients died or lost membership, follow-up period for the effectiveness outcome was until the end of 2019, whereas the safety outcome was for a period up to 1 year. Conditional logistic regression was used to analyze both outcomes. We identified 7818 patients who met the inclusion criteria and started DOAC, which matched to 7818 patients who did not receive anticoagulants. The mean age was 82.3 ± 5.1 years, and 51.5% male. The DOAC group had a lower hazard ratio of 0.37 (confidence interval, 0.24-0.57; P < 0.01) for composite effectiveness outcomes, whereas no difference in the composite safety outcome (hazard ratio, 0.91; confidence interval, 0.65-1.25; P = 0.55) when compared with matched control. In conclusion, DOAC was found to be effective in preventing thromboembolic events in patients aged 75+ years with nonvalvular atrial fibrillation who were not eligible for warfarin.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2.

OBJECTIVES: To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair. METHODS: A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed. RESULTS: Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively. CONCLUSIONS: The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

Comparative clinical study of short-term outcomes between table fenestrated and chimney endovascular aneurysm repair for hostile neck aneurysms.

OBJECTIVES: Hostile neck abdominal aortic aneurysm (AAA) is challenging for standard endovascular aneurysm repair (EVAR). We sought to compare fenestrated endovascular aneurysm repair (fEVAR) and chimney endovascular aneurysm repair (chEVAR) for hostile neck AAA. METHODS: Patients were identified retrospectively. Hostile neck anatomy was defined as a proximal neck length of <15 mm or angulation >60°. The choice of fEVAR or chEVAR was based on neck anatomy and physician preference. Type I endoleak (T1EL) was the primary outcome. Other outcomes included type III endoleak (T3EL), visceral stent occlusion, renal insufficiency, reintervention, and mortality. RESULTS: A total of 84 patients were included from April 2012 to December 2021. fEVAR and chEVAR patients were 48 and 36 cases, respectively. Both groups showed similar rate of T1EL, T3EL, visceral stent occlusion, renal insufficiency, reintervention, and mortality. However, chEVAR patients had a more tortuous neck (61.1% vs. 16.7%, p < 0.001), while fEVAR patients had a greater neck size (29.5 ± 6.3 mm vs. 24.5 ± 4.8 mm, p < 0.001) and more reconstructing target arteries (2.2 ± 1.1 vs 1.3 ± 0.6, p < 0.001). CONCLUSIONS: fEVAR and chEVAR show similar safe and effective outcomes in well-selected hostile neck. fEVAR might be able to reconstruct multiple visceral arteries, and chEVAR seems justified in patients with poor anatomical suitability for fEVAR.

Advances in the Experimental Models of HIV-Associated Neurological Disorders.

PURPOSE OF REVIEW: Involvement of the central nervous system (CNS) in HIV-1 infection is commonly associated with neurological disorders and cognitive impairment, commonly referred to as HIV-associated neurocognitive disorders (HAND). Severe and progressive neurocognitive impairment is rarely observed in the post-cART era; however, asymptomatic and mild neurocognitive disorders still exist, despite viral suppression. Additionally, comorbid conditions can also contribute to the pathogenesis of HAND. RECENT FINDINGS: In this review, we summarize the characterization of HAND, factors contributing, and the functional impairments in both preclinical and clinical models. Specifically, we also discuss recent advances in the animal models of HAND and in in vitro cultures and the potential role of drugs of abuse in this model system of HAND. Potential peripheral biomarkers associated with HAND are also discussed. Overall, this review identifies some of the recent advances in the field of HAND in cell culture studies, animal models, clinical findings, and the limitations of each model system, which can play a key role in developing novel therapeutics in the field.

Application of vermicompost and biochar suppresses Fusarium root rot of replanted American ginseng.

Soil sterilization integrated with agronomic measures is an effective method to reduce soilborne replant diseases. However, the effect of vermicompost or biochar application after soil sterilization on soilborne diseases is poorly understood. A pot experiment was conducted in American ginseng to investigate the effects of vermicompost (VF), biochar (BF), and a combination of vermicompost and biochar (VBF) applied after soil sterilization on the incidence of Fusarium root rot using natural recovery (F) as control. After one growing season, the disease index of root rot, the phenolic acids, and the microbial communities of American ginseng rhizosphere soil were analyzed. The disease index of VF, BF, and VBF decreased by 33.32%, 19.03%, and 80.96%, respectively, compared with F. The highest bacterial richness and diversity were observed in the rhizosphere soil of VBF. Besides, VF and VBF significantly increased the relative abundance of beneficial bacteria (Pseudomonas, Lysobacter, and Chryseolinea) in the rhizosphere soil. Higher concentrations of vanillin, one of the phenolic acids in the roots exudates, were recorded in the rhizosphere soils of BF and VBF. The vanillin concentration showed a significant negative correlation with the disease index. To conclude, vermicompost improved the beneficial bacteria of the rhizosphere soil, while biochar regulated the allelopathic effect of the phenolic acids. The study proposes a combined application of biochar and vermicompost to the rhizosphere soil to control Fusarium root rot of replanted American ginseng effectively. KEY POINTS: Vermicompost improves the relative abundance of rhizosphere beneficial bacteria. Biochar inhibits the degradation of phenolic acids by adsorption. The combination of vermicompost and biochar enhances the disease control effect.

Risk of Overdose with Exposure to Prescription Opioids, Benzodiazepines, and Non-benzodiazepine Sedative-Hypnotics in Adults: a Retrospective Cohort Study.

BACKGROUND: Concurrent use of benzodiazepines in opioid users has been linked to a higher risk of an emergency room visit or inpatient admission for opioid overdose and death from drug overdose. Further research is needed to confirm the findings and analyze contributing risk factors for opioid overdoses in a large commercially insured population. OBJECTIVES: To estimate the risk of opioid overdose associated with opioid users exposed to various combinations of opioid, benzodiazepine, and non-benzodiazepine sedative-hypnotic therapy. To identify other factors that are associated with increased risk for opioid overdose. DESIGN: Retrospective cohort study. PATIENTS: New start adult users of opioids, defined as naïve to opioids for 6 months, in Kaiser Permanente California regions from January 2013 through September 2017. MAIN MEASURES: Inpatient or emergency department admissions due to opioid-related overdose. KEY RESULTS: A total of 2,241,530 patients were included in this study. Patients exposed to opioids, benzodiazepines, and non-benzodiazepine sedative-hypnotics at any point during their follow-up were 60% more likely to overdose than those who were only exposed to opioids (p < 0.0001). Those exposed to opioids and benzodiazepines were 20% more likely to have an opioid-related overdose than those exposed to opioids only (p < 0.0001). Significant risk factors for opioid overdose included exposure to all three medication classes, higher opioid dosage strengths, elderly age (age ≥ 65 years), history of previous overdose, and substance use disorder. CONCLUSIONS: Results from this study demonstrate a significant increase in risk of opioid overdose in patients exposed to combinations of sedative-hypnotics with opioids compared to those only taking opioids. Findings from this study provide evidence that opioids should be avoided in combination with benzodiazepines and non-benzodiazepine sedative-hypnotics, used at the lowest dose possible, and used with caution in the elderly, those with previous history of overdose, and those with substance use disorder at baseline.

Baicalein triazole prevents respiratory tract infection by RSV through suppression of oxidative damage.

Baicalein, an isolate of secutellaria baicalensis is known for its anti-inflammatory activity. In the present study, 12-triazole derivatives of baicalein were synthesized and evaluated against RSV infected BEAS-2B cells in vitro and in mice model in vivo. The preventive effect of most active compound 5f against RSV infection was studied in detail. The compound 5f treatment increased IFN-ß1 expression in BEAS-2B cells infected with RSV. In BEAS-2B cells treatment with compound 5f inhibited RSV-induced secretion of interleukin-6 and -8 cytokines. It decreased RSV-induced nitric oxide & malondialdehyde production and inhibited the RSV-mediated activation of NF-κB, COX-2, Stat3 and MAPK. The p38 phosphorylation was enhanced significantly in RSV infected cells by compound 5f pre-treatment. RT-qPCR showed that compound 5f treatment of the RSV-infected mice significantly (P < 0.05) decreased viral load through reduction in the viral replication. In the mice model of RSV-infection compound 5f treatment decreased interleukin-6, -8 and tumor necrosis factor-α expression. The level of MPO, nitric oxide and malondialdehyde was also decreased significantly by compound 5f in the RSV infected mice BALF. It also reduced the infiltration of neutrophils and lymphocytes in the BALF of RVS-infected mice. In summary, compound 5f inhibits RSV-infection and prevents pulmonary airway inflammation through the activation of IFN signalling pathway.

Vibrational spectroscopic study of pH dependent solvation at a Ge(100)-water interface during an electrode potential triggered surface termination transition.

The charge-dependent structure of interfacial water at the n-Ge(100)-aqueous perchlorate interface was studied by controlling the electrode potential. Specifically, a joint attenuated total reflection infrared spectroscopy and electrochemical experiment was used in 0.1M NaClO4 at pH ≈ 1-10. The germanium surface transformation to an H-terminated surface followed the thermodynamic Nernstian pH dependence and was observed throughout the entire pH range. A singular value decomposition-based spectra deconvolution technique coupled to a sigmoidal transition model for the potential dependence of the main components in the spectra shows the surface transformation to be a two-stage process. The first stage was observed together with the first appearance of Ge-H stretching modes in the spectra and is attributed to the formation of a mixed surface termination. This transition was reversible. The second stage occurs at potentials ≈0.1-0.3 V negative of the first one, shows a hysteresis in potential, and is attributed to the formation of a surface with maximum Ge-H coverage. During the surface transformation, the surface becomes hydrophobic, and an effective desolvation layer, a "hydrophobic gap," developed with a thickness ≈1-3 Å. The largest thickness was observed near neutral pH. Interfacial water IR spectra show a loss of strongly hydrogen-bound water molecules compared to bulk water after the surface transformation, and the appearance of "free," non-hydrogen bound OH groups, throughout the entire pH range. Near neutral pH at negative electrode potentials, large changes at wavenumbers below 1000 cm-1 were observed. Librational modes of water contribute to the observed changes, indicating large changes in the water structure.

Electrode potential dependent desolvation and resolvation of germanium(100) in contact with aqueous perchlorate electrolytes.

The electrode potential dependence of the hydration layer on an n-Ge(100) surface was studied by a combination of in situ and operando electrochemical attenuated total reflection infrared (ATR-IR) spectroscopy and real space density functional theory (DFT) calculations. Constant-potential DFT calculations were coupled to a modified generalised Poisson-Boltzmann ion distribution model and applied within an ab initio molecular dynamics (AIMD) scheme. As a result, potential-dependent vibrational spectra of surface species and surface water were obtained, both experimentally and by simulations. The experimental spectra show increasing absorbance from the Ge-H stretching modes at negative potentials, which is associated with an increased negative difference absorbance of water-related OH modes. When the termination transition of germanium from OH to H termination occurs, the surface switches from hydrophilic to hydrophobic. This transition is fully reversible. During the switching, the interface water molecules are displaced from the surface forming a "hydrophobic gap". The gap thickness was experimentally estimated by a continuum electrodynamic model to be ≈2 Å. The calculations showed a shift in the centre of mass of the interface water by ≈0.9 Å due to the surface transformation. The resulting IR spectra of the interfacial water in contact with the hydrophobic Ge-H show an increased absorbance of free OH groups, and a decreased absorbance of strongly hydrogen bound water. Consequently, the surface transformation to a Ge-H terminated surface leads to a surface which is weakening the H-bond network of the interfacial water in contact.

Role of Sigma-1 Receptor in Cocaine Abuse and Neurodegenerative Disease.

Sigma-1 receptors (Sig-1R) are recognized as a unique class of non-G protein-coupled intracellular protein. Sig-1R binds to its ligand such as cocaine , resulting in dissociation of Sig-1R from mitochondrion-associated ER membrane (MAM) to the endoplasmic reticulum (ER), plasma membrane, and nuclear membrane, regulating function of various proteins. Sig-1R has diverse roles in both physiological as well as in pathogenic processes. The disruption of Sig-1R pathways has been implicated as causative mechanism(s) in the development of both neurodegenerative disorders such as Alzheimer disease (AD ), Parkinson disease (PD ), amyotrophic lateral sclerosis (ALS ) and Huntington Disease (HD ) . Additionally, the interaction of cocaine and Sig-1R has more recently been implicated in potentiating the pathogenesis of HIV-associated neurocognitive disorders (HAND) through impairment of blood-brain barrier (BBB), microglial activation and astrogliosis. On the other hand, restoration of Sig-1R homeostasis has been shown to exert neuroprotective effects. In this review, we provide an overview of how Sig-1R plays a role in the pathogenesis of neurodegenerative disorders and cocaine and implications for future development of therapeutic strategies.

A Frequency-Domain Adaptive Matched Filter for Active Sonar Detection.

The most classical detector of active sonar and radar is the matched filter (MF), which is the optimal processor under ideal conditions. Aiming at the problem of active sonar detection, we propose a frequency-domain adaptive matched filter (FDAMF) with the use of a frequency-domain adaptive line enhancer (ALE). The FDAMF is an improved MF. In the simulations in this paper, the signal to noise ratio (SNR) gain of the FDAMF is about 18.6 dB higher than that of the classical MF when the input SNR is -10 dB. In order to improve the performance of the FDAMF with a low input SNR, we propose a pre-processing method, which is called frequency-domain time reversal convolution and interference suppression (TRC-IS). Compared with the classical MF, the FDAMF combined with the TRC-IS method obtains higher SNR gain, a lower detection threshold, and a better receiver operating characteristic (ROC) in the simulations in this paper. The simulation results show that the FDAMF has higher processing gain and better detection performance than the classical MF under ideal conditions. The experimental results indicate that the FDAMF does improve the performance of the MF, and can adapt to actual interference in a way. In addition, the TRC-IS preprocessing method works well in an actual noisy ocean environment.

Reactive Oxygen Species/Hypoxia-Inducible Factor-1α/Platelet-Derived Growth Factor-BB Autocrine Loop Contributes to Cocaine-Mediated Alveolar Epithelial Barrier Damage.

Abuse of psychostimulants, such as cocaine, has been shown to be closely associated with complications of the lung, such as pulmonary hypertension, edema, increased inflammation, and infection. However, the mechanism by which cocaine mediates impairment of alveolar epithelial barrier integrity that underlies various pulmonary complications has not been well determined. Herein, we investigate the role of cocaine in disrupting the alveolar epithelial barrier function and the associated signaling cascade. Using the combinatorial electric cell-substrate impedance sensing and FITC-dextran permeability assays, we demonstrated cocaine-mediated disruption of the alveolar epithelial barrier, as evidenced by increased epithelial monolayer permeability with a concomitant loss of the tight junction protein zonula occludens-1 (Zo-1) in both mouse primary alveolar epithelial cells and the alveolar epithelial cell line, L2 cells. To dissect the signaling pathways involved in this process, we demonstrated that cocaine-mediated induction of permeability factors, platelet-derived growth factor (PDGF-BB) and vascular endothelial growth factor, involved reactive oxygen species (ROS)-dependent induction of hypoxia-inducible factor (HIF)-1α. Interestingly, we demonstrated that ROS-dependent induction of another transcription factor, nuclear factor erythroid-2-related factor-2, that did not play a role in cocaine-mediated barrier dysfunction. Importantly, this study identifies, for the first time, that ROS/HIF-1α/PDGF-BB autocrine loop contributes to cocaine-mediated barrier disruption via amplification of oxidative stress and downstream signaling. Corroboration of these cell culture findings in vivo demonstrated increased permeability of the alveolar epithelial barrier, loss of expression of Zo-1, and a concomitantly increased expression of both HIF-1α and PDGF-BB. Pharmacological blocking of HIF-1α significantly abrogated cocaine-mediated loss of Zo-1. Understanding the mechanism(s) by which cocaine mediates barrier dysfunction could provide insights into the development of potential therapeutic targets for cocaine-mediated pulmonary hypertension.