经食道心房调搏测定窦房结功能

对27例病窦综合征患者和42例正常对照组,经食道心房调搏,测定窦房结功能。发现病窦患者,窦房结恢复时间>1450ms;校正窦房结恢复时间≥550ms;窦房结传异时间>191ms;固有心率均明显低于正常对照组(R<0.01)。用阿托品,心得安进行功能性植物阻滞前、后观察,发现阻滞后各次参数在正常对照组中有明显降低,而病窦组则无明显差异。实验证明,经食道心房调搏方法是无创性窦房结功能检查的有效方法。     

Shear bond strength of five porcelain repair systems on cerec porcelain.

The purpose of this in vitro investigation was to evaluate the shear bond strength of composite resin bonded to Cerec Vitablocs Mark II porcelain with four different porcelain repair systems. The systems evaluated in this study were Scotchbond/ RelyX Primer (S/ 3M), Ultradent Porcelain Repair Kit (U, Ultradent), Vivadent Ceramic Repair Kit (V, Vivadent) and Prime & Bond NT/ Calibra Silane Coupling Agent (P, Dentsply). Seventy five Cerec Vitablocks Mark II porcelain were embedded in metal rings, leaving 7 mm of porcelain exposed above the ring surface. Samples were ground wet on 400 grit SiC paper to roughen the surface and then screened for surface defects. The five porcelain repair agents were applied according to manufacturers' instructions and matching composite stubbs, then bonded onto 15 treated porcelain surfaces, using an Ultradent mould with a diameter of 2,38 mm. All samples were stored in distilled water for 24 hours at 37 degrees C before the bonds were stressed to failure, using a shear load in a Texture Analyser (TAXT2i) (Stable Micro Systems) Data was analyzed statistically (ANOVA). The effects of the pretreatments on the porcelain surfaces after treatment with the different systems were examined in a Scanning Electron Microscope (SEM), and the modes of fracture were assessed under a light microscope. The mean SBS (MPa) for the products in descending order were: U = 26.6 1.7; V = 20.9 3.4; C = 19.4 5.3; S = 18.0 2.0 and P = 15.9 2.1. The Student-t Test revealed a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and U. There was also a statistical significant difference (p < 0.05) between the mean shear bond strengths of P and V. Most debonded specimens showed cohesive fractures in the porcelain. Significant shear bond strength differences were observed for the different repair systems. All the systems tested can probably be used to repair Cerec Vitablocs Mark II porcelain, with some systems providing higher bond strengths.     

Plasma HIV-1 RNA decline within the first two weeks of treatment is comparable for nevirapine, efavirenz, or both drugs combined and is not predictive of long-term virologic efficacy: A 2NN substudy

BACKGROUND: The initial rate of plasma HIV-1 RNA (pVL) decline has been proposed as a marker of early efficacy of antiretroviral therapy (ART) and a possible predictor of late efficacy. We compared the rate of pVL decline in patients starting ART with nevirapine (NVP), efavirenz (EFV), or both drugs combined in addition to lamivudine (3TC) and stavudine (d4T). METHODS: Analysis of the viral decay constant (VDc) during the first 2 weeks of treatment in patients enrolled in the 2NN study who remained on allocated treatment. RESULTS: The median VDc (log10 copies per day, [interquartile range]) was similar for NVP (0.30 [0.25-0.36], EFV (0.31 [0.27-0.37]), and NVP + EFV (0.30 [0.27-0.36]). Patients with a baseline pVL >100,000 copies/mL were 8.7 (95% confidence interval [CI]: 6.2-12.3) times more likely to have a VDc >75th percentile. A high VDc was not associated with plasma drug concentration or with a decreased risk of virologic failure at week 48 after the start of therapy (hazard ratio = 0.8, 95% CI: 0.6-1.2). CONCLUSION: NVP, EFV, or NVP + EFV in combination with 3TC and d4T show similar rates of pVL decline during the first 2 weeks of treatment. The VDc with these regimens is not predictive of late virologic efficacy.     

Complexities in the process of translating research documents in cross-cultural settings

ABSTRACT

In multilingual societies, where researchers and participants often do not speak the same language, research is a challenge as a mismatch of understanding between researchers, research instruments and participants often occurs. Reporting on the translation process is crucial because of the potential implications for the validity of the data that follow from it. We aimed to report on the complexities of such a translation process and many considerations that came to our attention. Methodologically, we used a detailed case study to demonstrate that the complexity of translation might be underestimated by researchers who may neglect to report on the challenges that they experience to benefit the wider research community. We emphasise that translating documents, particularly between languages that are not cognate, requires time and financial resources that researchers often do not anticipate or plan for. By discussing what happened to texts that were translated, and how we as researchers were challenged by considerations that were primarily linguistic but also straddled cultural and socio-political domains, we hope to encourage a deeper understanding of the translation task. We conclude that consideration of these complexities is necessary if the aim is the development of translated documents which complement the researchers’ goals.     

Use of the Patient State Index (PSI) to Assist in the Diagnosis of Perioperative Neurological Injury and Brain Death

We present a series of three postoperative cases that were admitted to a cardiothoracic intensive care unit (ICU) after major surgery. Due to the possible presence of residual postoperative neuromuscular blockade after surgery, a processed electroencephalograph (EEG) was applied prior to starting sedation. This was markedly abnormal in all three cases, and not in keeping with the residual anesthesia. The patients were immediately transported for a CT scan. In all three cases there was severe neurological injury incompatible with survival and end of life decisions were made. Although the utility of quantitative EEG technology, like the Bispectral index (BIS) or Patient State Analyzer (PSA), is becoming better defined in the operating room, the role in the ICU is less clear. We propose that the ICU use of the PSA 4000 may have affected our decision weighing the risk versus benefit of transporting a fresh postoperative case to the radiology suite, expedited the neurological diagnosis, and may have reduced overall ICU resource utilization.     

Ancient plant DNA reveals High Arctic greening during the Last Interglacial

Summer warming is driving a greening trend across the Arctic, with the potential for large-scale amplification of climate change due to vegetation-related feedbacks [Pearson et al., Nat. Clim. Chang. (3), 673–677 (2013)]. Because observational records are sparse and temporally limited, past episodes of Arctic warming can help elucidate the magnitude of vegetation response to temperature change. The Last Interglacial ([LIG], 129,000 to 116,000 y ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change [Otto-Bliesner et al., Philos. Trans. A Math. Phys. Eng. Sci. (371), 20130097 (2013) and Post et al., Sci. Adv. (5), eaaw9883 (2019)]. However, high-latitude terrestrial records from this period are rare, so LIG vegetation distributions are incompletely known. Pollen-based vegetation reconstructions can be biased by long-distance pollen transport, further obscuring the paleoenvironmental record. Here, we present a LIG vegetation record based on ancient DNA in lake sediment and compare it with fossil pollen. Comprehensive plant community reconstructions through the last and current interglacial (the Holocene) on Baffin Island, Arctic Canada, reveal coherent climate-driven community shifts across both interglacials. Peak LIG warmth featured a ∼400-km northward range shift of dwarf birch, a key woody shrub that is again expanding northward. Greening of the High Arctic—documented here by multiple proxies—likely represented a strong positive feedback on high-latitude LIG warming. Authenticated ancient DNA from this lake sediment also extends the useful preservation window for the technique and highlights the utility of combining traditional and molecular approaches for gleaning paleoenvironmental insights to better anticipate a warmer future.

The Arctic is greening as shrub biomass increases and vegetation ranges shift north in response to summer warming (1, 2). This process—one of the clearest terrestrial manifestations of climate change thus far—has major implications both for local ecosystems and for global energy balance and biogeochemical systems (3–5). In particular, taller shrubs darken otherwise snow-covered surfaces, contributing to the albedo feedback (6, 7), and enhanced evapotranspiration is expected to result in a positive greenhouse feedback (8). Shrub cover also impacts soil thermal regime, which may impact permafrost vulnerability (9–11). Because feedbacks related to Arctic greening are complex and potentially large in magnitude, estimating the extent and rate of northward shrub migration is a vital component of predicting future warming.Past warm periods serve as valuable analogs for understanding the extent of Arctic greening under well-constrained climate conditions. The Last Interglacial (LIG; Marine Isotope Stage [MIS] 5e, 129 to 116 ka [thousands of years before present]) was ∼1 °C warmer than the preindustrial period globally, but the Arctic experienced amplified warming due to higher summer insolation anomalies and positive feedbacks at high latitudes (12, 13). The Eastern Canadian Arctic and Greenland, in particular, were likely ∼4 to 8 °C warmer in summer than present (Fig. 1) (14–18). LIG sediment records from this region thus provide an archive of the vegetation response to Arctic warming at levels comparable to predicted 21^st-century climate change (19).Open in a separate windowFig. 1.Map of Baffin Island and Lake CF8 study area. The symbols represent maximum LIG temperature anomalies based on terrestrial proxy records (shape indicates proxy type) from Baffin Island and Greenland (see SI Appendix, Table S1 for metadata). The shaded regions indicate Arctic bioclimate subzones delineations (29), including modern Betula range in subzones D and E. We note that a small outlier population of Betula occurs east of the D/E boundary on Baffin Island (not captured by vegetation map resolution) (38).While most High Arctic lake basins were scraped clean by ice sheet erosion during the last glaciation and thus only contain postglacial sediments, lakes with small, low-relief catchments within regions of cold-based, slow-flowing ice were protected from erosion. Several such sites have been discovered on eastern Baffin Island, Arctic Canada and contain stratified records of multiple interglacials (20–22). Previous work from Lake CF8 on northeastern Baffin Island (Fig. 1 and SI Appendix, Fig. S1) demonstrates that its sediment record spans at least three interglacials (∼200 ka), including a substantially warmer-than-present LIG as indicated by chironomids, diatoms, and geochemical proxies (15, 23).We targeted the multi-interglacial record from Lake CF8 to assess the vegetation response to pronounced warmth during the LIG and moderate warmth during the Holocene. Pollen produced by some key shrubs and trees, including Betula (birch), is efficiently wind-transported and thus present in lake sediments far north of their ranges (24, 25). We therefore analyzed both sedimentary ancient DNA (sedaDNA), which is sourced locally from within the lake catchment and does not include pollen-derived DNA (26), and fossil pollen to generate a robust vegetation record spanning the last ∼130 ka. Taken together, DNA-inferred plant communities and pollen-inferred July air temperatures provide insight into Arctic plant range shifts under strong summer warming.     

Natural compulsive‐like behaviour in the deer mouse (Peromyscus maniculatus bairdii) is associated with altered gut microbiota composition

Obsessive–compulsive disorder (OCD) is a psychiatric illness that significantly impacts affected patients and available treatments yield suboptimal therapeutic response. Recently, the role of the gut–brain axis (GBA) in psychiatric illness has emerged as a potential target for therapeutic exploration. However, studies concerning the role of the GBA in OCD are limited. To investigate whether a naturally occurring obsessive–compulsive‐like phenotype in a rodent model, that is large nest building in deer mice, is associated with perturbations in the gut microbiome, we investigated and characterised the gut microbiota in specific‐pathogen‐free bred and housed large (LNB) and normal (NNB) nest‐building deer mice of both sexes (n = 11 per group, including three males and eight females). Following baseline characterisation of nest‐building behaviour, a single faecal sample was collected from each animal and the gut microbiota analysed. Our results reveal the overall microbial composition of LNB animals to be distinctly different compared to controls (PERMANOVA p < .05). While no genera were found to be significantly differentially abundant after correcting for multiple comparisons, the normal phenotype showed a higher loading of Prevotella and Anaeroplasma, while the OC phenotype demonstrated a higher loading of Desulfovermiculus, Aestuariispira, Peptococcus and Holdemanella (cut‐off threshold for loading at 0.2 in either the first or second component of the PCA). These findings not only provide proof‐of‐concept for continued investigation of the GBA in OCD, but also highlight a potential underlying aetiological association between alterations in the gut microbiota and the natural development of obsessive–compulsive‐like behaviours.     

2012～2013年合肥地区孕妇OGTT筛查结果分析

目的：调查合肥地区孕妇妊娠期糖代谢异常的发生率,探讨其相关高危因素,以及孕妇在妊娠期进行口服葡萄糖耐量试验（OGTT）筛查的意义。方法以1520例2012～2013年于该院门诊就诊的妊娠前无糖尿病、高血压、心脏病、肾脏疾病、血液系统疾病及其他系统疾病的孕妇为研究对象,进行75 g OGTT筛查,结合临床相关资料分析合肥地区孕妇妊娠期糖代谢异常发生的相关高危因素。结果1520例孕妇75 g OGTT筛查阳性率为5．78％,其中葡萄糖耐量降低发生率为2．50％,妊娠糖尿病（GDM）检出率为3．28％。高龄、孕前肥胖及糖尿病家族史为妊娠期孕妇糖代谢异常的相关高危因素。结论对孕妇进行OGTT筛查能够有效发现GDM高危孕妇,并可及早预防和减少GDM的相关并发症。