Ratiometric Fluorescence Aptasensor of Allergen Protein Based on Multivalent Aptamer-Encoded DNA Flowers as Fluorescence Resonance Energy Transfer Platform.

Life-threatening allergic reactions to food allergens, particularly peanut protein Ara h1, are a growing public health concern affecting millions of people worldwide. Thus, accurate and rapid detection is necessary for allergen labeling and dietary guidance and ultimately preventing allergic incidents. Herein, we present a novel ratiometric fluorescence aptasensor based on multivalent aptamer-encoded DNA flowers (Mul-DNFs) for the high-stability and sensitive detection of allergen Ara h1. The flower-shaped Mul-DNFs were spontaneously packaged using ultralong polymeric DNA amplicons driven by a rolling circle amplification reaction, which contains a large number of Ara h1 specific recognition units and has excellent binding properties. Furthermore, dual-color fluorescence-labeled Mul-DNFs probes were developed by hybridizing them with Cy3- and Cy5-labeled complementary DNA (cDNA) to serve as a ratiometric fluorescence aptasensor platform based on fluorescence resonance energy transfer. Benefiting from the combined merits of the extraordinary synergistic multivalent binding ability of Mul-DNFs, the excellent specificity of the aptamer, and the sensitivity of the ratiometric sensor to avoid exogenous interference. The developed ratiometric aptasensor showed excellent linearity (0.05-2000 ng mL-1) with a limit of detection of 0.02 ng mL-1. Additionally, the developed ratiometric fluorescence aptasensor was utilized for quantifying the presence of Ara h1 in milk, infant milk powder, cookies, bread, and chocolate with recoveries of 95.7-106.3%. The proposed ratiometric aptasensor is expected to be a prospective universal aptasensor platform for the rapid, sensitive, and accurate determination of food and environmental hazards.

JS-K Combined with a Melanin-Based Theranostic Agent: A Novel Sequential Delivery Strategy to Enhance the Near-Infrared Fluorescence Imaging of Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a 5 year survival rate less than 12%. This malignancy is closely related to the unique tumor microenvironment (TME), which is characterized by a hypovascular and hyperdense extracellular matrix, making it difficult for drugs to permeate the tumor center. Near-infrared fluorescence (NIRF) imaging, which has high sensitivity and resolution, may improve the survival rate of PDAC patients. In this study, we first used JS-K (O2-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazine-1-yl] diazene-1-ium-1,2-diolate) to specifically dilate blood vessels within the TME of PDAC patients and subsequently injected IR820-PEG-MNPs (IPM NPs) to diagnose and treat orthotopic PDAC. We found that JS-K promoted the accumulation of IPM NPs in orthotopic Pan02 tumor-bearing mice and was able to increase the tumor signal-to-background ratio (SBR) in the orthotopic PDAC area by 41.5%. In addition, surgical navigation in orthotopic Pan02 tumor-bearing mice and complete tumor resection based on fluorescence imaging were achieved with a detection sensitivity of 81.0%. Moreover, we verified the feasibility of the combination of laparoscopy and photothermal ablation (PTA) for the treatment of PDAC. Finally, we demonstrated that IPM NPs had greater affinity for human PDAC tissues than for normal pancreatic tissues ex vivo, preliminarily highlighting the potential for clinical translation of these NPs. In conclusion, we developed and validated a novel sequential delivery strategy that promotes the accumulation of nanoagents in the tumor area and can be used for the diagnosis and treatment of PDAC.

Biomimetic Capsid-Like Nanoshells Self-Assembled from Homopolypeptides.

The preparation of capsid-like nanoshells and the elucidation of their formation pathways are crucial for the application potential of capsid-like nanomaterials. In this study, we have prepared biomimetic capsid-like nanoshells (CLNs) through the solution self-assembly of poly (ß-phenethyl-L-aspartate) homopolypeptide (PPLA). The formation of CLNs is governed by an aggregation-fusion mechanism. Initially, PPLA molecules self-assemble into small spherical assemblies as subunits and the initial nuclei are formed through fusing some subunits. Subsequently, additional subunits rapidly fuse onto these nuclei, leading to the growth of full or partial CLNs during the growth phase. Moreover, the suitable condition benefiting CLNs formation is clarified by a morphological phase diagram based on the initial PPLA concentration against water content. Molecular-level measurements suggest that the molecular flexibility of PPLA is a key factor in the arrangement and fusion of subunits for the formation of CLNs. These findings offer new perspectives for a deeper understanding of the formation pathways of capsid-like nanoshells derived from synthetic polymers.

High ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 increases the risk of asthma attack in American asthma adults: a population study.

OBJECTIVE: The relationship between vitamin D3 and asthma remains controversial. However, previous studies have largely overlooked the impact of epi-25-(OH)-vitamin D3. This study aims to investigate the effects of different forms of vitamin D3 on asthma attack in adults. METHODS: In this cross-sectional study, a total of 3,873 eligible adult participants were extracted from the national health and nutrition examination survey (NHANES) database from 2007 to 2018. Based on quartiles method, different levels of vitamin D were divided into four groups (Quartile 1-4). Bivariate correlation analysis was performed for vitamin D and covariates to avoid multicollinearity. Multivariate logistic regression was used to investigate the association between serum levels of vitamin D3 (epi-25-(OH)-vitamin D3 and 25-(OH)-vitamin D3) and asthma attack, adjusting for covariates including age, gender, race, length of time in the U.S., house poverty income ratio (PIR), education level, smoking history, hypertension history, and diabetes history. The ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 was used for secondary analysis of its association with asthma attack. The outcomes were assessed by odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among the 3,873 eligible adults American with asthma, 1,508 (38.94%) had experienced at least one acute asthma attack in the past year. There was no significant correlation between vitamin D and covariates. After adjusting for covariates including age, gender, race, length of time in the U.S., house poverty income ratio (PIR), education level, smoking history, hypertension history and diabetes history, we found a positive correlation between the ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 and asthma attack. Additionally, a high ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 was more common among elder, male, of normal weight, non-Hispanic American, have a long time stay in the U.S., a high house PIR, and a history of hypertension individuals. CONCLUSION: Our findings suggest that attention should be given to asthma attack associated with a high ratio of epi-25-(OH)-vitamin D3 to 25-(OH)-vitamin D3 in American adults who are elderly, male, of normal weight, non-Hispanic Americans, have long-term residence in the U.S., a high house PIR, and a history of hypertension.

High-affinity truncated aptamers for detection of Cronobacter spp with magnetic separation-assisted DNAzyme-driven 3D DNA walker.

After optimizing the original aptamer sequence by truncation strategy, a magnetic separation-assisted DNAzyme-driven 3D DNA walker fluorescent aptasensor was developed for detecting the food-borne pathogen Cronobacter species. Iron oxide magnetic nanoparticles (MNPs) modified with a hybrid of truncated aptamer probe and DNAzyme strand (AP-E1) denoted as MNPs@AP-E1, were employed as capture probes. Simultaneously, a DNAzyme-driven 3D-DNA walker was utilized as the signal amplification element. The substrate strand (Sub) was conjugated with the gold nanoparticles (AuNPs), resulting in the formation of AuNPs@Sub, which served as a 3D walking track. In the presence of the target bacteria and Mg2+, E1-DNAzyme was activated and moved along AuNPs@Sub, continuously releasing the signal probe. Under optimized conditions, a strong linear correlation was observed for Cronobacter sakazakii (C. sakazakii) in the concentration range 101 to 106 CFU mL-1, with a low detection limit of 2 CFU mL-1. The fluorescence signal responses for different Cronobacter species exhibited insignificant differences, with a relative standard deviation of 3.6%. Moreover, the aptasensor was successfully applied to determine  C. sakazakii in real samples with recoveries of 92.86%-108.33%. Therefore, the novel method could be a good candidate for ultra-sensitive and selective detection of Cronobacter species without complex manipulation.

Conductive Polymer Coated Layered Double Hydroxide as a Novel Sulfur Reservoir for Flexible Lithium-Sulfur Batteries.

Lithium-sulfur battery (LSB) is widely regarded as the most promising next-generation energy storage system owing to its high theoretical capacity and low cost. However, the practical application of LSBs is mainly hampered by the low electronic conductivity of the sulfur cathode and the notorious "shuttle effect", which lead to high voltage polarization, severe over-charge behavior, and rapid capacity decay. To address these issues, a novel sulfur reservoir is synthesized by coating polypyrrole (PPy) thin film on hollow layered double hydroxide (LDH) (PPy@LDH). After compositing with sulfur, such PPy@LDH-S cathode shows a multi-functional effect to reserve lithium polysulfides (LiPSs). In addition, the unique architecture provides sufficient inner space to encapsulate the volume expansion and enhances the reaction kinetics of sulfur-based redox chemistry. Theoretical calculations have illustrated that the PPy@LDH has shown stronger chemical adsorption capability for LiPSs than those of porous carbon and LDH, preventing the shuttling of LiPSs and enhancing the nucleation affinity of liquid-solid conversion. As a result, the PPy@LDH-S electrode delivers a stable cycling performance and a superior rate capability. Flexible battery has demonstrated this PPy@LDH-S electrode can work properly with treatments of bending, folding, and even twisting, paving the way for wearable devices and flexible electronics.

Key transition technology of ski jumping based on inertial motion unit, kinematics and dynamics.

BACKGROUND: The development and innovation of biomechanical measurement methods provide a solution to the problems in ski jumping research. At present, research on ski jumping mostly focuses on the local technical characteristics of different phases, but studies on the technology transition process are less. OBJECTIVES: This study aims to evaluate a measurement system (i.e. the merging of 2D video recording, inertial measurement unit and wireless pressure insole) that can capture a wide range of sport performance and focus on the key transition technical characteristics. METHODS: The application validity of the Xsens motion capture system in ski jumping was verified under field conditions by comparing the lower limb joint angles of eight professional ski jumpers during the takeoff phase collected by different motion capture systems (Xsens and Simi high-speed camera). Subsequently, the key transition technical characteristics of eight ski jumpers were captured on the basis of the aforementioned measurement system. RESULTS: Validation results indicated that the joint angle point-by-point curve during the takeoff phase was highly correlated and had excellent agreement (0.966 ≤ r ≤ 0.998, P < 0.001). Joint root-mean-square error (RMSE) differences between model calculations were 5.967° for hip, 6.856° for knee and 4.009° for ankle. CONCLUSIONS: Compared with 2D video recording, the Xsens system shows excellent agreement to ski jumping. Furthermore, the established measurement system can effectively capture the key transition technical characteristics of athletes, particularly in the dynamic changes of straight turn into arc in inrun, the adjustment of body posture and ski movement during early flight and landing preparation.

A novel clinical prediction model of severity based on red cell distribution width, neutrophil-lymphocyte ratio and intra-abdominal pressure in acute pancreatitis in pregnancy.

BACKGROUND: Acute pancreatitis in pregnancy (APIP) with a high risk of death is extremely harmful to mother and fetus. There are few models specifically designed to assess the severity of APIP. Our study aimed to establish a clinical model for early prediction of severity of APIP. METHODS: A retrospective study in a total of 188 patients with APIP was enrolled. The hematological indicators, IAP (intra-abdominal pressure) and clinical data were obtained for statistical analysis and prediction model construction. RESULTS: According to univariate and multivariate logistic regression analysis, we found that red cell distribution width (RDW), neutrophil-lymphocyte ratio (NLR) and Intra-abdominal pressure (IAP) are prediction indexes of the severity in APIP (p-value < 0.05). Our novel clinical prediction model was created by based on the above three risk factors and showed superior predictive power in primary cohort (AUC = 0.895) and validation cohort (AUC = 0.863). A nomogram for severe acute pancreatitis in pregnancy (SAPIP) was created based on the three indicators. The nomogram was well-calibrated. CONCLUSION: RDW, NLR and IAP were the independent risk factors of APIP. Our clinical prediction model of severity in APIP based on RDW, NLR and IAP with predictive evaluation is accurate and effective.

Rational design of NIR-II molecule-engineered nanoplatform for preoperative downstaging and imaging-guided surgery of orthotopic hepatic tumor.

Orthotopic advanced hepatic tumor resection without precise location and preoperative downstaging may cause clinical postoperative recurrence and metastasis. Early accurate monitoring and tumor size reduction based on the multifunctional diagnostic-therapeutic integration platform could improve real-time imaging-guided resection efficacy. Here, a Near-Infrared II/Photoacoustic Imaging/Magnetic Resonance Imaging (NIR-II/PAI/MRI) organic nanoplatform IRFEP-FA-DOTA-Gd (IFDG) is developed for integrated diagnosis and treatment of orthotopic hepatic tumor. The IFDG is designed rationally based on the core "S-D-A-D-S" NIR-II probe IRFEP modified with folic acid (FA) for active tumor targeting and Gd-DOTA agent for MR imaging. The IFDG exhibits several advantages, including efficient tumor tissue accumulation, good tumor margin imaging effect, and excellent photothermal conversion effect. Therefore, the IFDG could realize accurate long-term monitoring and photothermal therapy non-invasively of the hepatic tumor to reduce its size. Next, the complete resection of the hepatic tumor in situ lesions could be realized by the intraoperative real-time NIR-II imaging guidance. Notably, the preoperative downstaging strategy is confirmed to lower the postoperative recurrence rate of the liver cancer patients under middle and advanced stage effectively with fewer side effects. Overall, the designed nanoplatform demonstrates great potential as a diagnostic-therapeutic integration platform for precise imaging-guided surgical navigation of orthotopic hepatic tumors with a low recurrence rate after surgery, providing a paradigm for diagnosing and treating the advanced tumors in the future clinical translation application.

A novel ternary Y-DNA walker amplification strategy designed fluorescence aptasensor based on Au@SiO2@Fe3O4 nanomaterials for ochratoxin A detection.

A novel ternary Y-DNA walker amplification strategy designed fluorescence aptasensor based on Au@SiO2@Fe3O4 nanomaterials for ultrasensitive and specific ochratoxin A detection in food samples is presented. Au@SiO2@Fe3O4 nanomaterials provide the loading platform as well as separation and recovery properties for the ternary Y-DNA walker. The ternary Y-DNA walker is designed to be driven by Nb.BbvCI cleaving a large number of FAM probes to achieve signal amplification. Since Ochratoxin A (OTA) can bind to the constituent aptamer in the ternary Y-DNA walker, adding OTA will destroy the structure of the ternary Y-DNA walker, thereby inhibiting the driving process of the walker. After optimization of various parameters, a standard curve was obtained from 100 to 0.05 ng·mL-1 of OTA with the limit of determination of 0.027 ng·mL-1. The spiked recovery of peanut samples by this method was 82.00-93.30%, and the aptasensor showed excellent specificity and long-term stability. This simple, robust, and scalable oligonucleotide chain-based ternary Y-DNA walker can provide a general signal amplification strategy for trace analysis.

Application of a new multi-element integrated teaching mode based on bite-sized teaching, flipped classroom, and MOOC in clinical teaching of obstetrics and gynaecology.

CONTEXT: Effective clinical medical student education includes attention to teaching approaches. This study assessed the impact of a new multi-element teaching mode that utilizes Bite-Sized Teaching, flipped classroom, and MOOC on learner perception in an Obstetrics and gynaecology clerkship. METHODS: A Two-stage crossover design study was conducted of a multi-element teaching mode compared to traditional teaching mode in an academic year. Participants included Ninety-six medical students practicing obstetrics and gynecology in our hospital, randomly divided into two groups respectively underwent multi-element teaching mode and traditional teaching mode. After each semester, a final test (including theoretical and clinical practical test) was conducted.When an academic year was completed, post intervention survey assessed learner perceptions of the intervention. RESULT: In order to comprehensively test students' performance after study, we take theoretical and practical examinations. The theoretical examination mainly tests students' grasp of basic knowledge points, while the practical examination focuses on the examination of students' diagnosis and treatment of diseases. There were statistically significant differences both in the theoretical and clinical practical scores between the new multi-element integrated teaching mode and the traditional teaching mode, specifically as follows: In the end of first semester, the theoretical scores of the two groups were respective 43.75 ± 3.42 vs. 42.07 ± 2.90, and clinic practical test scores were respective 44.93 ± 2.42 vs. 43.37 ± 2.52; In the end of second semester, the theoretical scores of the two groups were respective 44.30 ± 2.69 vs. 42.25 ± 3.39, and clinic practical test scores were respective 43.79 ± 2.25 vs. 41.93 ± 2.80.(p < 0.05). The results of questionnaires demonstrated that 80.21% of the students showed preference for the new multi-element integrated teaching mode comparing to traditional teaching methods. CONCLUSION: The new multi-element integrated teaching mode is well accepted by the students and can improve the students' mastery of knowledge, and can improve the students' clinical comprehensive ability. The new multi-element integrated teaching mode is shown more preference than traditional teaching mode in the teaching of Obstetrics and Gynaecology. Further long term study is needed carried out to consolidate our conclusion. The new multi-element integrated teaching mode may have positive effects on clinical teaching of Obstetrics and Gynaecology.

Advances in riboswitch-based biosensor as food samples detection tool.

Food safety has always been a hot issue of social concern, and biosensing has been widely used in the field of food safety detection. Compared with traditional aptamer-based biosensors, aptamer-based riboswitch biosensing represents higher precision and programmability. A riboswitch is an elegant example of controlling gene expression, where the target is coupled to the aptamer domain, resulting in a conformational change in the downstream expression domain and determining the signal output. Riboswitch-based biosensing can be extensively applied to the portable real-time detection of food samples. The numerous key features of riboswitch-based biosensing emphasize their sustainability, renewable, and testing, which promises to transform engineering applications in the field of food safety. This review covers recent developments in riboswitch-based biosensors. The brief history, definition, and modular design (regulatory mode, reporter, and expression platform) of riboswitch-based biosensors are explained for better insight into the design and construction. We summarize recent advances in various riboswitch-based biosensors involving theophylline, malachite green, tetracycline, neomycin, fluoride, thrombin, naringenin, ciprofloxacin, and paromomycin, aiming to provide general guidance for the design of riboswitch-based biosensors. Finally, the challenges and prospects are also summarized as a way forward stratagem and signs of progress.

Diradicaloid Boron-Doped Molecular Carbons Achieved by Pentagon-Fusion.

Molecular carbons (MCs) are molecular cutouts of carbon materials. Doping with heteroatoms and constructing open-shell structures are two powerful approaches to achieve unexpected and unique properties of MCs. Herein, we disclose a new strategy to design open-shell boron-doped MCs (BMCs), namely by pentagon-fusion of an organoborane π-system. We synthesized two diradicaloid BMC molecules that feature C24 B and C38 B π-skeletons containing a pentagonal ring. A thorough investigation reveals that such pentagon-fusion not only leads to their local antiaromaticity, but also incorporates an internal quinoidal substructure and thereby induces open-shell singlet diradical states. Moreover, their fully fused structures enable efficient π conjugation, which is expanded over the whole frameworks. Consequently, some intriguing physical properties are achieved, such as narrow energy gaps, very broad light absorptions, and superior photothermal capability, along with excellent photostability. Notably, the solid of the C38 B molecule exhibits absorption that covers the range of 300-1200 nm and an efficiency of 93.5 % for solar-driven water evaporation, thus demonstrating the potential of diradicaloid BMCs as high-performance organic photothermal materials.

Ru- and Cl-Codoped Li3 V2 (PO4 )3 with Enhanced Performance for Lithium-Ion Batteries in a Wide Temperature Range.

Li3 V2 (PO4 )3 (LVP) is a promising cathode material for lithium-ion batteries, especially when used in a wide temperature range, due to its high intrinsic ionic mobility and theoretical capacity. Herein, Ru- and Cl-codoped Li3 V2 (PO4 )3 (LVP-Rux -Cl3 x ) coated with/without a nitrogen-doped carbon (NC) layer are synthesized. Among them, the optimized sample (LVP-Ru0.05 -Cl0.15 @NC) delivers remarkable performances at both room temperature and extreme temperatures (-40, 25, and 60 °C), indicating temperature adaptability. It achieves intriguing capacities (49 mAh g-1 at -40 °C, 128 mAh g-1 at 25 °C, and 123 mAh g-1 at 60 °C, all at 0.5 C), long cycle life (94% capacity retention after 2000 cycles at 25 °C and 5 C), and high-rate capabilities (up to 20 C). The structural evolution features and capacity loss mechanisms of LVP-Ru0.05 -Cl0.15 @NC are further investigated using in situ X-ray diffraction (XRD) at different temperatures (-10, 25, and 60 °C) during redox reactions. Theoretical calculations elucidate that Ru- and Cl-codoping can greatly improve the intrinsic diffusion coefficient of LVP by reducing its bandgap energy and lowering the energy barrier of lithium-ion diffusion. In "all-weather" conditions, the dual-element co-doping strategy is critical for increasing electrochemical performance.

The effect of hydration and dehydration on the conformation, assembling behavior and photoluminescence of PBLG.

Hydration and dehydration play crucial roles in hydrophobic effects (HEs) and are yet to be understood. Poly(γ-benzyl-L-glutamate) (PBLG) homopolymers in THF/water with various water contents were investigated. We discovered that PBLG was hydrated at low water contents and adopted a helical conformation. The chain became dehydrated with increasing water content, which converted the PBLG100 helix to a PPII-helix. The variation in the conformation resulted in an alteration of the self-assembled morphologies from fibers to particles. For PBLG12 with a shorter chain, the chain underwent an α-to-ß transition in the conformation due to dehydration as the water content increased, and correspondingly the morphologies varied from tapes to helical ribbons, and eventually to toroids at a higher water content. We also observed that this α-to-ß transition is accompanied by an increase in intensity of the fluorescence, which is attributed to the through-space-conjugation of tightly packed phenyl groups within the ß-sheet. The discovered effect of hydration and dehydration on the PBLG chain conformation, self-assembling behavior and optical function is essential for the innovation of polypeptide materials and understanding of water-mediated biological systems.

Accurate prediction of microvascular invasion occurrence and effective prognostic estimation for patients with hepatocellular carcinoma after radical surgical treatment.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide, with an overall 5-year survival rate of less than 18%, which may be related to tumor microvascular invasion (MVI). This study aimed to compare the clinical prognosis of HCC patients with or without MVI after radical surgical treatment, and further analyze the preoperative risk factors related to MVI to promote the development of a new treatment strategy for HCC. METHODS: According to the postoperative pathological diagnosis of MVI, 160 study patients undergoing radical hepatectomy were divided into an MVI-negative group (n = 68) and an MVI-positive group (n = 92). The clinical outcomes and prognosis were compared between the two groups, and then the parameters were analyzed by multivariate logistic regression to construct an MVI prediction model. Then, the practicability and validity of the model were evaluated, and the clinical prognosis of different MVI risk groups was subsequently compared. RESULT: There were no significant differences between the MVI-negative and MVI-positive groups in clinical baseline, hematological, or imaging data. Additionally, the clinical outcome comparison between the two groups presented no significant differences except for the pathological grading (P = 0.002) and survival and recurrence rates after surgery (P < 0.001). The MVI prediction model, based on preoperative AFP, tumor diameter, and TNM stage, presented superior predictive efficacy (AUC = 0.7997) and good practicability (high H-L goodness of fit, P = 0.231). Compared with the MVI high-risk group, the patients in the MVI low-risk group had a higher survival rate (P = 0.002) and a lower recurrence rate (P = 0.004). CONCLUSION: MVI is an independent risk factor for a poor prognosis after radical resection of HCC. The MVI prediction model, consisting of AFP, tumor diameter, and TNM stage, exhibits superior predictive efficacy and strong clinical practicability for MVI prediction and prognostication, which provides a new therapeutic strategy for the standardized treatment of HCC patients.

Regulating the morphology and size of homopolypeptide self-assemblies via selective solvents.

It remains a great challenge to control the morphology and size of self-assembled homopolypeptide aggregates. In this work, rod-like micelles including spindles and cylinders were prepared by a solution self-assembly of poly(γ-benzyl-l-glutamate) (PBLG) homopolypeptides with different degrees of polymerization, in which their size was controlled precisely by tuning the ratio of water/methanol in selective cosolvents. The length of the rod-like micelles increased with an increasing amount of methanol in the selective cosolvents, which was confirmed using the combination of SEM, TEM and AFM. The self-assembly mechanism of PBLG in selective cosolvents was investigated by using complementary Fourier transform infrared (FT-IR), circular dichroism (CD) and low-field NMR analyses. It was found that the shrinkage and swelling of PBLG chains play important roles in the self-assembly process. The obtained results may provide a guideline for the study of regulating the assembled aggregate sizes.

Screening and application of a broad-spectrum aptamer for acyclic guanosine analogues.

Acyclic guanosine analogues, a class of widely used antiviral drugs, can cause chronic toxicity and virus resistance. Therefore, it is essential to establish rapid and accurate methods to detect acyclic guanosine analogues. In this study, five acyclic guanosine analogues (acyclovir, famciclovir, ganciclovir, penciclovir, and valaciclovir) were used as positive targets to obtain broad-spectrum aptamers through Capture-SELEX technology. Real-time quantitative PCR (Q-PCR) was used to monitor the aptamer SELEX process. After the sixteen rounds of selection against mixed targets, sequences were obtained by high-throughput sequencing (HTS). Furthermore, a broad-spectrum aptamer, named CIV6, was found as the higher performance aptamer that was suitable for five acyclic guanosine analogues by graphene oxide (GO) polarization and fluorescence assay. Finally, the aptamer CIV6 was used to construct GO fluorescence assay to detect five acyclic guanosine analogues. The limits of detection (LOD) of acyclovir, famciclovir, ganciclovir, penciclovir, and valaciclovir were 0.48 ng·mL-1, 0.53 ng·mL-1, 0.50 ng·mL-1, 0.56 ng·mL-1, and 0.38 ng·mL-1, respectively.

Base-Mediated Amination of Alcohols Using Amidines.

Novel and efficient base-mediated N-alkylation and amidation of amidines with alcohols have been developed, which can be carried out in one-pot reaction conditions, which allows for the synthesis of a wide range of N-alkyl amines and free amides in good to excellent yields with high atom economy. In contrast to borrowing hydrogen/hydrogen autotransfer or oxidative-type N-alkylation reactions, in which alcohols are activated by transition-metal-catalyzed or oxidative aerobic dehydrogenation, the use of amidines provides an effective surrogate of amines. This circumvents the inherent necessity in N-alkylation of an oxidant or a catalyst to be stabilized by ligands.

Concordance Study in Hepatectomy Recommendations Between Watson for Oncology and Clinical Practice for Patients with Hepatocellular Carcinoma in China.

BACKGROUND: With the improvement in diagnostic imaging, perioperative care and surgical technique, the indications and complexity of liver resections have developed. However, the surgical indications remain controversial especially for some complex or advanced hepatocellular carcinomas. This study was designed to evaluate the concordance between hepatectomy recommendations proposed by Watson for Oncology, a cognitive technology providing decision support, and those determined by surgeons in our center for patients with hepatocellular carcinoma. METHODS: We retrospectively reviewed 243 patients with hepatocellular carcinoma who were recommended for surgical treatment and received hepatectomy between 2008 and 2016 at the Zhujiang Hospital of Southern Medical University. Watson for Oncology classified the treatment options into three categories: recommended, for consideration and not recommended. Treatment recommendations were considered concordant if the hepatectomy recommendations were designated "recommended" or "for consideration" by Watson for Oncology. The factors potentially affecting concordance rate were also analyzed in our study. RESULTS: The hepatectomy recommendations of 174 patients were concordant. There were significant differences in the coincidence rate between concordant group and discordant group considering tumor numbers (P = 0.006), extension of hepatectomy (P = 0.009) and BCLC staging system (P < 0.001). Lower degrees of concordance were observed in patients with multiple tumors, major hepatectomy and portal hypertension by using logistic regression analysis (OR = 0.309, P = 0.004; OR = 0.384, P = 0.004; and OR = 0.376, P = 0.022, respectively). CONCLUSION: The concordance between Watson for Oncology and surgeons' hepatectomy recommendation for hepatocellular carcinoma was only 72%. Differences in practice patterns for HCC between the USA (where Watson for Oncology was calibrated) and China may be the major cause of discordance. Watson for Oncology still requires further improvement and localization to be widely applied in China.