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With the rapid development of biomaterials and biotechnologies, various functional materials-based drug delivery systems (DDS) are developed to overcome the limitations of traditional drug release formulations, such as uncontrollable drug concentration in target organs/tissues and unavoidable adverse reactions. Polymer nanofibers exhibit promising characteristics including easy preparation, adjustable features of wettability and elasticity, tailored surface and interface properties, and surface-to-volume ratio, and are used to develop new DDS. Different kinds of drugs can be incorporated into the polymer nanofibers. Additionally, their release kinetics can be modulated via the preparation components, component proportions, and preparation processes, enabling their applications in several fields. A timely and comprehensive summary of polymeric nanofibers for DDS is thus highly needed. This review first describes the common methods for polymer nanofiber fabrication, followed by introducing controlled techniques for drug loading into and release from polymer nanofibers. Thus, the applications of polymer nanofibers in drug delivery were summarized, particularly focusing on the relation between the physiochemical properties of polymeric nanofibers and their DDS performance. It is ended by listing future perspectives.

Upper gastrointestinal cancers (including oesophageal cancer and gastric cancer) are the most common cancers worldwide. Artificial intelligence platforms using deep learning algorithms have made remarkable progress in medical imaging but their application in upper gastrointestinal cancers has been limited. We aimed to develop and validate the Gastrointestinal Artificial Intelligence Diagnostic System (GRAIDS) for the diagnosis of upper gastrointestinal cancers through analysis of imaging data from clinical endoscopies. This multicentre, case-control, diagnostic study was done in six hospitals of different tiers (ie, municipal, provincial, and national) in China. The images of consecutive participants, aged 18 years or older, who had not had a previous endoscopy were retrieved from all participating hospitals. All patients with upper gastrointestinal cancer lesions (including oesophageal cancer and gastric cancer) that were histologically proven malignancies were eligible for this study. Only images with standard white light were deemed eligible. The images from Sun Yat-sen University Cancer Center were randomly assigned (8:1:1) to the training and intrinsic verification datasets for developing GRAIDS, and the internal validation dataset for evaluating the performance of GRAIDS. Its diagnostic performance was evaluated using an internal and prospective validation set from Sun Yat-sen University Cancer Center (a national hospital) and additional external validation sets from five primary care hospitals. The performance of GRAIDS was also compared with endoscopists with three degrees of expertise: expert, competent, and trainee. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of GRAIDS and endoscopists for the identification of cancerous lesions were evaluated by calculating the 95% CIs using the Clopper-Pearson method. 1 036 496 endoscopy images from 84 424 individuals were used to develop and test GRAIDS. The diagnostic accuracy in identifying upper gastrointestinal cancers was 0·955 (95% CI 0·952–0·957) in the internal validation set, 0·927 (0·925–0·929) in the prospective set, and ranged from 0·915 (0·913–0·917) to 0·977 (0·977–0·978) in the five external validation sets. GRAIDS achieved diagnostic sensitivity similar to that of the expert endoscopist (0·942 [95% CI 0·924–0·957] vs 0·945 [0·927–0·959]; p=0·692) and superior sensitivity compared with competent (0·858 [0·832–0·880], p<0·0001) and trainee (0·722 [0·691–0·752], p<0·0001) endoscopists. The positive predictive value was 0·814 (95% CI 0·788–0·838) for GRAIDS, 0·932 (0·913–0·948) for the expert endoscopist, 0·974 (0·960–0·984) for the competent endoscopist, and 0·824 (0·795–0·850) for the trainee endoscopist. The negative predictive value was 0·978 (95% CI 0·971–0·984) for GRAIDS, 0·980 (0·974–0·985) for the expert endoscopist, 0·951 (0·942–0·959) for the competent endoscopist, and 0·904 (0·893–0·916) for the trainee endoscopist. GRAIDS achieved high diagnostic accuracy in detecting upper gastrointestinal cancers, with sensitivity similar to that of expert endoscopists and was superior to that of non-expert endoscopists. This system could assist community-based hospitals in improving their effectiveness in upper gastrointestinal cancer diagnoses. The National Key R&D Program of China, the Natural Science Foundation of Guangdong Province, the Science and Technology Program of Guangdong, the Science and Technology Program of Guangzhou, and the Fundamental Research Funds for the Central Universities.

ObjectiveHepatitis D virus (HDV) is a defective virus that completes its life cycle only with hepatitis B virus (HBV). The HBV with HDV super-infection has been considered as one of the most severe forms of the chronic viral hepatitis. However, there is a scarcity of data on the global burden of HDV infection.DesignWe searched PubMed, Embase, Cochrane Library and China Knowledge Resource Integrated databases from 1 January 1977 to 31 December 2016. We included studies with a minimum sample size of 50 patients. Our study analysed data from a total of 40 million individuals to estimate the prevalence of HDV by using Der-Simonian Laird random-effects model. The data were further categorised according to risk factors.ResultsFrom a total of 2717 initially identified studies, only 182 articles from 61 countries and regions met the final inclusion criteria. The overall prevalence of HDV was 0.98% (95% CI 0.61 to 1.42). In HBsAg-positive population, HDV pooled prevalence was 14.57% (95% CI 12.93 to 16.27): Seroprevalence was 10.58% (95% CI 9.14 to 12.11) in mixed population without risk factors of intravenous drug use (IVDU) and high-risk sexual behaviour (HRSB). It was 37.57% (95% CI 29.30 to 46.20) in the IVDU population and 17.01% (95% CI 10.69 to 24.34) in HRSB population.ConclusionWe found that approximately 10.58% HBsAg carriers (without IVDU and HRSB) were coinfected with HDV, which is twofold of what has been estimated before. We also noted a substantially higher HDV prevalence in the IVDU and HRSB population. Our study highlights the need for increased focus on the routine HDV screening and rigorous implementation of HBV vaccine programme.

Direct protein sequencing technologies with improved sensitivity and throughput are still needed. Here, we propose an alternative method for peptide sequencing based on enzymatic cleavage and host–guest interaction-assisted nanopore sensing. We serendipitously discovered that the identity of any proteinogenic amino acid in a particular position of a phenylalanine-containing peptide could be determined via current blockage during translocation of the peptide through α-hemolysin nanopores in the presence of cucurbit[7]uril. Building upon this, we further present a proof-of-concept demonstration of peptide sequencing by sequentially cleaving off amino acids from C terminus of a peptide with carboxypeptidases, and then determining their identities and sequence with a peptide probe in nanopore. With future optimization, our results point to a different way of nanopore-based protein sequencing. A phenylalanine-containing peptide probe can be used for discriminating all 20 amino acids via current blockage during translocation through an α-hemolysin (αHL) nanopore. The paper provides proof-of-concept peptide sequencing demonstrations.

An important issue in nanopore sensing is to construct stable and versatile sensors that can discriminate analytes with minute differences. Here we report a means of creating nanopores that comprise ultrashort single-walled carbon nanotubes inserted into a lipid bilayer. We investigate the ion transport and DNA translocation through single-walled carbon nanotube nanopores and find that our results are fundamentally different from previous studies using much longer single-walled carbon nanotubes. Furthermore, we utilize the new single-walled carbon nanotube nanopores to selectively detect modified 5-hydroxymethylcytosine in single-stranded DNA, which may have implications in screening specific genomic DNA sequences. This new nanopore platform can be integrated with many unique properties of carbon nanotubes and might be useful in molecular sensing such as DNA-damage detection, nanopore DNA sequencing and other nanopore-based applications. Nanopore sensors are a promising tool for the controlled detection of a range of possible substrates. Here the authors describe a nanopore sensor based on short single-walled carbon nanotubes inserted into a lipid bilayer, with modified sensing properties compared to longer nanotubes.

Age is an important risk factor for breast cancer, but data regarding whether patient age at diagnosis is related to breast cancer survival are conflicting. This population-based study evaluated the effect of age on breast cancer prognosis and identified outcome-related factors. We searched the Surveillance, Epidemiology, and End Results (SEER) database and enrolled female primary non-metastatic cases. Patients were subdivided into seven groups, and analyses of the associations between age and overall survival (OS) and breast cancer-specific survival (BCSS) were carried out using the Kaplan-Meier method and Cox regression model, respectively. We also assessed differences in survival among three specific age groups, using the ages of 30 and 50 years as cut-offs. Stratified analyses regarding race, histology, grade, stage and hormone receptor status were also carried out. A total of 133,057 female patients diagnosed with breast cancer from 2004 to 2008 were included in the current study (6.4% <40 years), Women aged 40 to 49 years and 60 to 69 years exhibited significantly better OS and BCSS, respectively (log-rank, p<0.001), than their counterparts in other groups. Middle-aged women exhibited distinctly better OS (log-rank, p<0.001) and BCSS (log-rank, p<0.001) than their counterparts in the other two age groups. Following adjustments for potential confounding factors, middle-age at breast cancer diagnosis was shown to be an independent predictor of favourable outcomes in terms of OS, but not BCSS (for OS, HR, 0.92; 95%CI, 0.87-0.98; p = 0.007; for BCSS, HR, 0.94; 95%CI, 0.80-1.01; p = 0.075, using the young group as reference). Stratified analysis showed that middle-age was significantly associated with increased survival, except among patients with stage III disease, and that elderly women faced worse prognoses than younger patients. Our results indicate that younger breast cancer patients exhibit more aggressive disease than older patients. Middle-aged patients exhibit better OS and BCSS than young and elderly patients but exhibit BCSS rates similar to those of young patients after adjustments for confounders. Stratified analysis demonstrated that middle-aged patients exhibited better survival than young patients, with the exception of patients with stage III disease. An age of 60 years or more was a significant independent predictor of a poor prognosis.

Recently, 'Liquid crystal display (LCD) vs. organic light-emitting diode (OLED) display: who wins?' has become a topic of heated debate. In this review, we perform a systematic and comparative study of these two flat panel display technologies. First, we review recent advances in LCDs and OLEDs, including material development, device configuration and system integration. Next we analyze and compare their performances by six key display metrics: response time, contrast ratio, color gamut, lifetime, power efficiency, and panel flexibility. In this section, we focus on two key parameters: motion picture response time (MPRT) and ambient contrast ratio (ACR), which dramatically affect image quality in practical application scenarios. MPRT determines the image blur of a moving picture, and ACR governs the perceived image contrast under ambient lighting conditions. It is intriguing that LCD can achieve comparable or even slightly better MPRT and ACR than OLED, although its response time and contrast ratio are generally perceived to be much inferior to those of OLED. Finally, three future trends are highlighted, including high dynamic range, virtual reality/augmented reality and smart displays with versatile functions.

Exhaustion of cytotoxic effector natural killer (NK) and CD8 + T cells have important functions in the establishment of persistent viral infections, but how exhaustion is induced during chronic hepatitis C virus (HCV) infection remains poorly defined. Here we show, using the humanized C/O Tg mice permissive for persistent HCV infection, that NK and CD8 + T cells become sequentially exhausted shortly after their transient hepatic infiltration and activation in acute HCV infection. HCV infection upregulates Qa-1 expression in hepatocytes, which ligates NKG2A to induce NK cell exhaustion. Antibodies targeting NKG2A or Qa-1 prevents NK exhaustion and promotes NK-dependent HCV clearance. Moreover, reactivated NK cells provide sufficient IFN-γ that helps rejuvenate polyclonal HCV CD8 + T cell response and clearance of HCV. Our data thus show that NKG2A serves as a critical checkpoint for HCV-induced NK exhaustion, and that NKG2A blockade sequentially boosts interdependent NK and CD8 + T cell functions to prevent persistent HCV infection. Immune cells may become less responsive, or ‘exhausted’, upon chronic viral infection, but the underlying mechanism and crosstalk are still unclear. Here the authors show that, upon chronic hepatitis C virus (HCV) infection, natural killer cell exhaustion is induced by NKG2A signalling to instruct downstream exhaustion of CD8 + T cells and HCV persistence.

We propose an efficient high-throughput scheme for the discovery of stable crystalline phases. Our approach is based on the transmutation of known compounds, through the substitution of atoms in the crystal structure with chemically similar ones. The concept of similarity is defined quantitatively using a measure of chemical replaceability, extracted by data-mining experimental databases. In this way we build 189,981 possible crystal phases, including 18,479 that are on the convex hull of stability. The resulting success rate of 9.72% is at least one order of magnitude better than the usual success rate of systematic high-throughput calculations for a specific family of materials, and comparable with speed-up factors of machine learning filtering procedures. As a characterization of the set of 18,479 stable compounds, we calculate their electronic band gaps, magnetic moments, and hardness. Our approach, that can be used as a filter on top of any high-throughput scheme, enables us to efficiently extract stable compounds from tremendously large initial sets, without any initial assumption on their crystal structures or chemical compositions.

Intervertebral disc degeneration (IDD) is a common clinical degenerative disease of the spine. A series of factors, such as inflammation, oxidative stress and mechanical stress, promote degradation of the extracellular matrix (ECM) of the intervertebral discs (IVD), leading to dysfunction and structural destruction of the IVD. Nuclear factor‐κB (NF‐κB) transcription factor has long been regarded as a pathogenic factor of IDD. Therefore, NF‐κB may be an ideal therapeutic target for IDD. As NF‐κB is a multifunctional functional transcription factor with roles in a variety of biological processes, a comprehensive understanding of the function and regulatory mechanism of NF‐κB in IDD pathology will be useful for the development of targeted therapeutic strategies for IDD, which can prevent the progression of IDD and reduce potential risks. This review discusses the role of the NF‐κB signalling pathway in the nucleus pulposus (NP) in the process of IDD to understand pathological NP degeneration further and provide potential therapeutic targets that may interfere with NF‐κB signalling for IDD therapy. Intervertebral disc degeneration (IDD) is a common clinical degenerative disease of the spine. A series of factors, such as inflammation, oxidative stress, and mechanical stress, promote degradation of the extracellular matrix (ECM) of the intervertebral discs (IVD), leading to dysfunction and structural destruction of the IVD. Nuclear factor‐κB (NF‐κB) transcription factor has long been regarded as the pathogenic factor of IDD. Therefore, NF‐κB may be an ideal therapeutic target for IDD. As NF‐κB is a multifunctional functional transcription factor with roles in a variety of biological processes, a comprehensive understanding of the function and regulatory mechanism of NF‐κB in IDD pathology will be useful for the development of targeted therapeutic strategies for IDD, which can prevent the progression of IDD and reduce potential risks. This review discusses the role of the NF‐κB signalling pathway in the nucleus pulposus (NP) in the process of IDD to understand pathological NP degeneration further and provide potential therapeutic targets that may interfere with NF‐κB signalling for IDD therapy. ​