Engineering industrial yeast for improved tolerance and robustness

As an important cell factory, industrial yeast has been widely used for the production of compounds ranging from bulk chemicals to complex natural products. However, various adverse conditions including toxic products, extreme pH, and hyperosmosis etc., severely restrict microbial growth and metabolic performance, limiting the fermentation efficiency and diminishing its competitiveness. Therefore, enhancing the tolerance and robustness of yeasts is critical to ensure reliable and sustainable production of metabolites in complex industrial production processes. In this review, we provide a comprehensive review of various strategies for improving the tolerance of yeast cells, including random mutagenesis, system metabolic engineering, and material-mediated immobilization cell technology. It is expected that this review will provide a new perspective to realize the response and intelligent regulation of yeast cells to environmental stresses.

Recent Advances in Real-Time Label-Free Detection of Small Molecules

The detection and analysis of small molecules, typically defined as molecules under 1000 Da, is of growing interest ranging from the development of small-molecule drugs and inhibitors to the sensing of toxins and biomarkers. However, due to challenges such as their small size and low mass, many biosensing technologies struggle to have the sensitivity and selectivity for the detection of small molecules. Notably, their small size limits the usage of labeled techniques that can change the properties of small-molecule analytes. Furthermore, the capability of real-time detection is highly desired for small-molecule biosensors' application in diagnostics or screening. This review highlights recent advances in label-free real-time biosensing technologies utilizing different types of transducers to meet the growing demand for small-molecule detection.

Development of tandem antigen capture ELISAs measuring QSOX1 isoforms in plasma and serum

QSOX1 is a sulfhydryl oxidase that has been identified as a potential biomarker in multiple cancer types as well as acute decompensated heart failure. Three anti-QSOX1 monoclonal antibodies (mAbs) were generated: 2F1, 3A10, and 56-3. MAbs 2F1 and 3A10 were generated against the short isoform of recombinant QSOX1 (rQSOX1-S), and mAb 56-3 was generated against a peptide (NEQEQPLGQWHLS) from the long isoform of QSOX1 (QSOX1-L). Using these mAbs, tandem antigen capture ELISAs were developed to quantify both short and long isoforms of QSOX1 (Total QSOX1 ELISA) and QSOX1-L (QSOX1-L ELISA) in serum and plasma samples. The Total QSOX1 ELISA pairs mAbs 2F1 and 3A10 and has a limit of detection of 109.5 pM, while the QSOX1-L ELISA pairs mAbs 2F1 and 56-3 and has a limit of detection of 10 pM. The levels of total QSOX1 and QSOX1-L were measured in a cohort of paired sera and plasma from 61 donors ≥40 years old and 15 donors <40 years old. No difference in QSOX1 levels was detected between QSOX1-L and QSOX1-S in serum, but the mean concentration of QSOX1-L was found to be 3.21 nM in serum and 5.63 nM in plasma (**p = 0.006). Our tandem ELISAs demonstrate the wide range of concentrations of QSOX1-L and QSOX1-S among individual serum and plasma samples. Since the epitope of mAb 2F1 was mapped to the first CxxC motif at residues C70 and C73 and mAb 56-3 was generated against NEQEQPLGQWHLS in QSOX1-L, our findings support previous research which suggested that QSOX1-L is secreted from cells despite a putative transmembrane domain. The ELISAs reported here may be a useful tool for investigating QSOX1 isoforms as potential biomarkers in cancer and/or heart failure.

Ligand Binding-Induced Cellular Membrane Deformation is Correlated with the Changes in Membrane Stiffness

Study interaction between ligands and protein receptors is a key step for biomarker research and drug discovery. In situ measurement of cell surface membrane protein binding on whole cells eliminates the cost and pitfalls associated with membrane protein purification. Ligand binding to membrane protein was recently found to induce nanometer-scale cell membrane deformations, which can be monitored with real-time optical imaging to quantify ligand/protein binding kinetics. However, the insight into this phenomenon has still not been fully understood. We hypothesize that ligand binding can change membrane stiffness, which induces membrane deformation. To investigate this, cell height and membrane stiffness changes upon ligand binding are measured using atomic force microscopy (AFM). Wheat germ agglutinin (WGA) is used as a model ligand that binds to the cell surface glycoprotein. The changes in cell membrane stiffness and cell height upon ligand bindings are determined for three different cell lines (human A431, HeLa, and rat RBL-2H3) on two different substrates. AFM results show that cells become stiffer with increased height after WGA modification for all cases studied. The increase in cell membrane stiffness is further confirmed by plasmonic scattering microscopy, which shows an increased cell spring constant upon WGA binding. Therefore, this study provides direct experimental evidence that the membrane stiffness changes are directly correlated with ligand binding-induced cell membrane deformation.

Clinical Outcomes of Sidewall/Parametrial Simultaneous Integrated Boost for Patients with Cervical Cancer

PURPOSE/OBJECTIVE(S)

In the treatment of cervical cancer, simultaneous integrated boost (SIB) is a common technique to deliver increased dose to gross disease in the para-aortic and pelvic nodal basins. However, SIB to the pelvic sidewall/parametria is not well characterized in the literature. We hypothesized that sidewall simultaneous integrated boost (SIB) in the treatment of cervical cancer is associated with acceptable levels of toxicity.

MATERIALS/METHODS

From 1/2009-12/2018, patients who received concurrent chemoradiation with external beam radiation therapy, utilizing a sidewall SIB technique, followed by low dose rate or high dose rate brachytherapy treatment were retrospectively identified. Sidewall SIB was defined as treatment at 2.1-2.4Gy/fraction to the parametria-usually performed for those with disease width >4cm at time of treatment start. Acute and late toxicity grading was defined by the Common Terminology Criteria for Adverse Events Version 5.0. Overall survival (OS), local control, progression-free survival (PFS), and toxicity were analyzed utilizing the Kaplan Meier method. Potential associations between cumulative D2cc for bladder and rectum and time to toxicity were investigated using Cox regression.

RESULTS

Fifty-six patients with IB2-IVB cervical cancer treated with sidewall SIB were identified, with a median follow up of 7.0 years (95% CI: 6.3, 8.3). Patients had a median age of 43 years (range: 26-68); 2 (3.6%) had FIGO stage I, 7 (12.5%) stage II, 46 (82.1%) stage III, and 1 (1.8%) stage IV disease. A majority had squamous cell histology (83.9%). Nearly all patients (96.4%) received concurrent cisplatin chemotherapy. Rates of acute grade ≥3 gastrointestinal (GI), genitourinary (GU), vaginal, and hematologic toxicity were 1.8%, 1.8%, 0%, and 15.9% respectively. Rates of late grade ≥3 GI, GU, and vaginal toxicity were 11.3%, 18.5%, and 11.1% respectively. OS and local control rates at five years were 0.61 (95% CI: 0.46, 0.73) and 0.95 (95% CI: 0.84, 0.98), respectively. Median PFS was 7.8 years (95% CI: 2.4, Not reached). Cumulative D2cc bladder was not significantly associated with time to Grade 2 or greater (HR 1.04, p = 0.33) or Grade 3 or greater (HR 1.02; p = 0.64) GU toxicity. Cumulative D2cc rectum was not significantly associated with time to Grade 2 or greater (HR 1.06, p = 0.06) or Grade 3 or greater (HR 1.08; p = 0.09) GI toxicity.

CONCLUSION

Sidewall SIB is a feasible technique for dose escalation in the treatment of cervical cancer with rates of acute and late toxicity consistent with other reports.

Intracranial Control with Combined Dual Immune-Checkpoint Blockade and SRS for Melanoma and NSCLC Brain Metastases

PURPOSE/OBJECTIVE(S)

It is unknown whether the use of dual immune-checkpoint inhibition (D-ICI) combined with stereotactic radiosurgery (SRS) affects local control of brain metastases (BMs). We sought to characterize the efficacy of SRS and D-ICI in patients with BMs in a large, single-institution cohort.

MATERIALS/METHODS

Patients with melanoma and non-small cell lung cancer (NSCLC) BMs treated with SRS from January 1, 2016 to August 1, 2022 were evaluated. Patients were stratified by treatment with D-ICI versus single ICI (S-ICI). Concurrent ICI was defined as ICI given within four weeks of SRS. Local recurrence (LR), intracranial progression (IP), and overall survival (OS) were estimated using competing risk and Kaplan-Meier analyses. IP included both local and distant intracranial recurrence.

RESULTS

One thousand seven hundred four SRS-treated BMs from 288 patients met inclusion criteria. 55% of patients were symptomatic from their BMs at presentation. Median age, KPS, number of lesions, and SRS courses were 64 (Q1Q3:56-70.5), 90 (80-90), 2 (1-4), and 1 (1-2), respectively. One hundred twenty-eight (44%) melanoma and 160 (56%) NSCLC patients were included. 82 (28.5%), 129 (44.8%), and 77 (26.7%) patients were treated with D-ICI, S-ICI, or SRS alone. Median SRS dose, fractions, and PTV were 20 (Q1Q3:20-25), 1 (1-5), and 0.3cc3 (0.1-1.2). The median follow-up was 14.3 months. One hundred twenty-seven (7.45%) BMs recurred post-SRS and the median time to LR was 4.8 months (Q1Q3:3.0-9.2). On competing risk analysis, LR was significantly reduced with D-ICI (HR: 0.452, p = 0.0024), but not with S-ICI (HR: 0.693, p = 0.0596) compared to SRS alone. The 1-year LR was 3.77% (95% CI = 2.19-6.00), 6.8% (5.19-8.70), and 8.96% (6.48-11.93) with D-ICI, S-ICI, and SRS alone. The median time to IP was 4.1 months (Q1Q3 = 2.9-9.5). On competing risk analysis, IP was significantly reduced with D-ICI (HR = 0.638, p = 0.031), but not with S-ICI (HR = 0.756, p = 0.106) compared to SRS alone. 1-year IP was 40.05% (95% CI = 29.14-50.70), 51.86% (42.78-60.19), and 58.49% (46.30-68.84) with D-ICI, S-ICI, and SRS alone. Concurrent delivery of D-ICI and SRS significantly reduced IP (HR = 0.463, p = 0.0071), whereas other combinations of timing and ICI did not reach significance. Median OS was 11.9 months after SRS. On Kaplan Meier analysis, OS was significantly improved with D-ICI (HR = 0.616, 95% CI = 0.412-0.923, p = 0.019), but not with S-ICI (HR = 0.877, 95% CI = 0.633-1.217, p = 0.433) compared to SRS alone. Hospitalizations (p = 0.021) and immune-related adverse events (irAEs) (p<0.001) were increased with D-ICI. Any grade radiation necrosis (RN) was also increased with D-ICI (p = 0.013), but neurologic adverse events were comparable across cohorts (p = 0.572).

CONCLUSION

D-ICI combined with SRS was associated with improved local control, intracranial control, and overall survival compared to SRS alone, whereas S-ICI was not associated with an improvement in these outcomes. However, D-ICI was also associated with increased risks of irAEs and RN.

High-affinity binding to the SARS-CoV-2 spike trimer by a nanostructured, trivalent protein-DNA synthetic antibody

Multivalency enables nanostructures to bind molecular targets with high affinity. Although antibodies can be generated against a wide range of antigens, their shape and size cannot be tuned to match a given target. DNA nanotechnology provides an attractive approach for designing customized multivalent scaffolds due to the addressability and programmability of the nanostructure shape and size. Here, we design a nanoscale synthetic antibody ("nano-synbody") based on a three-helix bundle DNA nanostructure with one, two, or three identical arms terminating in a mini-binder protein that targets the SARS-CoV-2 spike protein. The nano-synbody was designed to match the valence and distance between the three receptor binding domains (RBDs) in the spike trimer, in order to enhance affinity. The protein-DNA nano-synbody shows tight binding to the wild-type, Delta, and several Omicron variants of the SARS-CoV-2 spike trimer, with affinity increasing as the number of arms increases from one to three. The effectiveness of the nano-synbody was also verified using a pseudovirus neutralization assay, with the three-arm nanostructure inhibiting two Omicron variants against which the structures with only one or two arms are ineffective. The structure of the three-arm nano-synbody bound to the Omicron variant spike trimer was solved by negative-stain transmission electron microscopy reconstruction, and shows the protein-DNA nanostructure with all three arms attached to the RBD domains, confirming the intended trivalent attachment. The ability to tune the size and shape of the nano-synbody, as well as its potential ability to attach two or more different binding ligands, will enable the high-affinity targeting of a range of proteins not possible with traditional antibodies.

Enhanced 1,3-propanediol production with high yield from glycerol through a novel Klebsiella-Shewanella co-culture

BACKGROUND

1,3-Propanediol (1,3-PDO) is a platform compound, which has been widely used in food, pharmaceutical and cosmetic industries. Compared with chemical methods, the biological synthesis of 1,3-PDO has shown promising applications owing to its mild conditions and environmental friendliness. However, the biological synthesis of 1,3-PDO still has the problem of low titer and yield due to the shortage of reducing powers.

RESULTS

In this study, Klebsiella sp. strain YT7 was successfully isolated, which can synthesize 11.30 g/L of 1,3-PDO from glycerol in flasks. The intracellular redox regulation strategy based on the addition of electron mediators can increase the 1,3-PDO titer to 28.01 g/L. Furthermore, a co-culturing system consisting of strain YT7 and Shewanella oneidensis MR-1 was established, which can eliminate the supplementation of exogenous electron mediators and reduce the by-products accumulation. The 1,3-PDO yield reached 0.44 g/g and the final titer reached 62.90 g/L. The increased titer and yield were attributed to the increased redox levels and the consumption of by-products.

CONCLUSIONS

A two-bacterium co-culture system with Klebsiella sp. strain YT7 and S. oneidensis strain MR-1 was established, which realized the substitution of exogenous electron mediators and the reduction of by-product accumulation. Results provided theoretical basis for the high titer of 1,3-PDO production with low by-product concentration.

HISMD: A Novel Immune Subtyping System for HNSCC

Immune subtyping is an important way to reveal immune heterogeneity, which may contribute to the diversity of the progression and treatment in head and neck squamous cell carcinoma (HNSCC). However, reported immune subtypes mainly focus on levels of immune infiltration and are mostly based on a mono-omics profile. This study aimed to identify a comprehensive immune subtype for HNSCC via multi-omics clustering and build a novel subtype prediction system for clinical application. Data were obtained from The Cancer Genome Atlas database and our independent multicenter cohort. Multi-omics clustering was performed to identify 3 clusters of 499 patients in The Cancer Genome Atlas based on immune-related gene expression and somatic mutations. The immune characteristics and biological features of the obtained clusters were revealed by bioinformatics, and 3 immune subtypes were identified: 1) adaptive immune activation subtype predominantly enriched in T cells, 2) innate immune activation subtype predominantly enriched in macrophages, and 3) immune desert subtype. Subsequently, the clinical implications of each subtype were analyzed per clinical epidemiology. We found that adaptive immune activation showed better survival outcomes and had a similar response to chemotherapy with innate immune activation, whereas immune desert might be relatively resistant to chemotherapy. Moreover, a subtype prediction system was developed by deep learning with whole slide images and named HISMD: HNSCC Immune Subtypes via Multi-omics and Deep Learning. We endowed HISMD with interpretability through image-based key feature extraction. The clinical implications, biological significances, and predictive stability of HISMD were successfully verified by using our independent multicenter cohort data set. In summary, this study revealed the immune heterogeneity of HNSCC and obtained a novel, highly accurate, and interpretable immune subtyping prediction system. For clinical implementation in the future, additional validation and utility studies are warranted.

Multiplexed Protein Detection and Parallel Binding Kinetics Analysis with Label-Free Digital Single-Molecule Counting

Multiplexed protein detection is critical for improving the drug and biomarker screening efficiency. Here, we show that multiplexed protein detection and parallel protein interaction analysis can be realized by evanescent scattering microscopy (ESM). ESM enables binding kinetics measurement with label-free digital single-molecule counting. We implemented an automatic single-molecule counting strategy with high temporal resolution to precisely determine the binding time, which improves the counting efficiency and accuracy. We show that digital single-molecule counting can recognize proteins with different molecular weights, thus making it possible to monitor the protein binding processes in the solution by real-time tracking of the numbers of free and bound proteins landing on the sensor surface. Furthermore, we show that this strategy can simultaneously analyze the kinetics of two different protein interaction processes on the surface and in the solution. This work may pave a way to investigate complicated protein interactions, such as the competition of biomarker-antibody binding in biofluids with biomarker-protein binding on the cellular membrane.

Label-Free Multimetric Measurement of Molecular Binding Kinetics by Electrical Modulation of a Flexible Nanobiolayer

Most label-free techniques rely on measuring refractive index or mass change on the sensor surface. Thus, it is challenging for them to measure small molecules or enzymatic processes that only induce a minor mass change on the analyte molecules. Here, we have developed a technique by combining Surface Plasmon Resonance sensing with an Oscillating Biomolecule Layer approach (SPR-OBL) to enhance the sensitivity of traditional SPR. In addition to the inherent mass sensitivity, SPR-OBL is also sensitive to the charge and conformational change of the analyte; hence it overcomes the mass limit and is able to detect small molecules. We show that the multimetric SPR-OBL measurement allows for sensing any changes regarding mass, charge, and conformation, which expands the detection capability of SPR.

Label-free imaging and biomarker analysis of exosomes with plasmonic scattering microscopy

Exosome analysis is a promising tool for clinical and biological research applications. However, detection and biomarker quantification of exosomes is technically challenging because they are small and highly heterogeneous. Here, we report an optical approach for imaging exosomes and quantifying their protein markers without labels using plasmonic scattering microscopy (PSM). PSM can provide improved spatial resolution and distortion-free image compared to conventional surface plasmon resonance (SPR) microscopy, with the signal-to-noise ratio similar to objective coupled surface plasmon resonance (SPR) microscopy, and millimeter-scale field of view as a prism-coupled SPR system, thus allowing exosome size distribution analysis with high throughput. In addition, PSM retains the high specificity and surface sensitivity of the SPR sensors and thus allows selection of exosomes from extracellular vesicles with antibody-modified sensor surfaces and in situ analyzing binding kinetics between antibody and the surface protein biomarkers on the captured exosomes. Finally, the PSM can be easily constructed on a popular prism-coupled SPR system with commercially available components. Thus, it may provide an economical and powerful tool for clinical exosome analysis and exploration of fundamental issues such as exosome biomarker binding properties.

Rapid Regulation of Local Temperature and Transient Receptor Potential Vanilloid 1 Ion Channels with Wide-Field Plasmonic Thermal Microscopy

Plasmonic absorption of light can create significant local heat and has become a promising tool for rapid temperature regulation in diverse fields, from biomedical technology to optoelectronics. Current plasmonic heating usually relies on specially designed nanomaterials randomly distributed in the space and barely provides uniform temperature regulation in a wide field. Herein, we report a rapid temperature regulation strategy on a plain gold-coated glass slip using a plasmonic scattering microscopy, which can be referred to as wide-field plasmonic thermal microscopy (W-PTM). We calibrated the W-PTM by monitoring the phase transition of the temperature-sensitive polymer solutions, showing that it can provide a temperature regulation range of 33-80 °C. Moreover, the W-PTM provides imaging capability, thus allowing the statistical analysis of the phase-transitioned polymeric nanoparticles. Finally, we demonstrated that W-PTM can be used for noninvasive and local regulation of the transient receptor potential vanilloid 1 (TRPV1) ion channels in the living cells, which can be monitored by simultaneous fluorescence imaging of the calcium influx. With the nondestructive local temperature-regulating and concurrent fluorescence imaging capability, we anticipate that W-PTM can be a powerful tool to study cellular activities associated with cellular membrane temperature changes.

Single Protein Detection and Imaging with Evanescent Scattering Microscopy

Single-molecule measurements provide statistical distributions of molecular properties, in addition to the ensemble averages. Evanescent detection approaches have been widely used for single-molecule detection because the evanescent field can significantly enhance the light-analyte interaction and reduce the background noise. However, current evanescent single-molecule detection systems mostly require specially designed sensing components. Here, we show that single proteins can be imaged on a plain cover glass surface by detecting the evanescent waves scattered by the target molecules. This allows us to quantify the protein-antibody interactions at the single-molecule level. This protocol describes a label-free single-molecule imaging approach with conventional consumables and may pave the road for detecting single molecules with commercial optical microscopy.

In Situ Analysis of Membrane-Protein Binding Kinetics and Cell-Surface Adhesion Using Plasmonic Scattering Microscopy

Surface plasmon resonance microscopy (SPRM) is an excellent platform for in situ studying cell-substrate interactions. However, SPRM suffers from poor spatial resolution and small field of view. Herein, we demonstrate plasmonic scattering microscopy (PSM) by adding a dry objective on a popular prism-coupled surface plasmon resonance (SPR) system. PSM not only retains SPRM's high sensitivity and real-time analysis capability, but also provides ≈7 times higher spatial resolution and ≈70 times larger field of view than the typical SPRM, thus providing more details about membrane protein response to ligand binding on over 100 cells simultaneously. In addition, PSM allows quantifying the target movements in the axial direction with a high spatial resolution, thus allowing mapping adhesion spring constants for quantitatively describing the mechanical properties of the cell-substrate contacts. This work may offer a powerful and cost-effective strategy for upgrading current SPR products.

Label-Free Single-Molecule Pulldown for the Detection of Released Cellular Protein Complexes

Precise and sensitive detection of intracellular proteins and complexes is key to the understanding of signaling pathways and cell functions. Here, we present a label-free single-molecule pulldown (LFSMP) technique for the imaging of released cellular protein and protein complexes with single-molecule sensitivity and low sample consumption down to a few cells per mm². LFSMP is based on plasmonic scattering imaging and thus can directly image the surface-captured molecules without labels and quantify the binding kinetics. In this paper, we demonstrate the detection principle for LFSMP, study the phosphorylation of protein complexes involved in a signaling pathway, and investigate how kinetic analysis can be used to improve the pulldown specificity. We wish our technique can contribute to uncovering the molecular mechanisms in cells with single-molecule resolution.

Single-Protein Identification by Simultaneous Size and Charge Imaging Using Evanescent Scattering Microscopy

Separation and identification of different proteins is one of the most fundamental tasks in biochemistry that is typically achieved by electrophoresis and Western blot techniques. Yet, it is challenging to perform such an analysis with a small sample size. Using a principle analogous to these conventional approaches, we present a label-free, single-molecule technique to identify different proteins based on the difference in their size, charge, and antibody binding. We tether single protein molecules to a sensor surface with a flexible polymer and drive them into oscillation by applying an alternating electric field. By tracking the nanometer-scale oscillation of each protein molecule via high-resolution scattering microscopy, the size and charge of each protein molecule can be determined simultaneously. Changes induced by varying the buffer pH and antibody binding are also investigated, which allows us to further expand the separation ability and identify two different proteins in a mixture. We anticipate our technique will contribute to single protein analysis and biosensing.

A Long Short-Term Memory-Based Approach for Detecting Turns and Generating Road Intersections from Vehicle Trajectories

Owing to the widespread use of GPS-enabled devices, sensing road information from vehicle trajectories is becoming an attractive method for road map construction and update. Although the detection of intersections is critical for generating road networks, it is still a challenging task. Traditional approaches detect intersections by identifying turning points based on the heading changes. As the intersections vary greatly in pattern and size, the appropriate threshold for heading change varies from area to area, which leads to the difficulty of accurate detection. To overcome this shortcoming, we propose a deep learning-based approach to detect turns and generate intersections. First, we convert each trajectory into a feature sequence that stores multiple motion attributes of the vehicle along the trajectory. Next, a supervised method uses these feature sequences and labeled trajectories to train a long short-term memory (LSTM) model that detects turning trajectory segments (TTSs), each of which indicates a turn occurring at an intersection. Finally, the detected TTSs are clustered to obtain the intersection coverages and internal structures. The proposed approach was tested using vehicle trajectories collected in Wuhan, China. The intersection detection precision and recall were 94.0% and 91.9% in a central urban region and 94.1% and 86.7% in a semi-urban region, respectively, which were significantly higher than those of the previously established local G* statistic-based approaches. In addition to the applications for road map development, the newly developed approach may have broad implications for the analysis of spatiotemporal trajectory data.

Label-Free Imaging of Single Proteins and Binding Kinetics Using Total Internal Reflection-Based Evanescent Scattering Microscopy

Single-molecule detection can push beyond ensemble averages and reveal the statistical distributions of molecular properties. Measuring the binding kinetics of single proteins also represents one of the critical and challenging tasks in protein analysis. Here, we report total internal reflection-based evanescent scattering microscopy with label-free single-protein detection capability. Total internal reflection is employed to excite the evanescent field to enhance light-analyte interaction and reduce environmental noise. As a result, the system provides wide-field imaging capability and allows excitation and observation using one objective. In addition, this system quantifies protein binding kinetics by simultaneously counting the binding of individual molecules and recording their binding sites with nanometer precision, providing a digital method to measure binding kinetics with high spatiotemporal resolution. This approach does not employ specially designed microspheres or nanomaterials and may pave a way for label-free single-protein analysis in conventional microscopy.

Three-Dimensional Tracking of Tethered Particles for Probing Nanometer-Scale Single-Molecule Dynamics Using a Plasmonic Microscope

Three-dimensional (3D) tracking of surface-tethered single particles reveals the dynamics of the molecular tether. However, most 3D tracking techniques lack precision, especially in the axial direction, for measuring the dynamics of biomolecules with a spatial scale of several nanometers. Here, we present a plasmonic imaging technique that can track the motion of ∼100 tethered particles in 3D simultaneously with sub-nanometer axial precision and single-digit nanometer lateral precision at millisecond time resolution. By tracking the 3D coordinates of a tethered particle with high spatial resolution, we are able to determine the dynamics of single short DNA and study its interaction with enzymes. We further show that the particle motion pattern can be used to identify specific and nonspecific interactions in immunoassays. We anticipate that our 3D tracking technique can contribute to the understanding of molecular dynamics and interactions at the single-molecule level.

Label-Free Imaging of Nanoscale Displacements and Free-Energy Profiles of Focal Adhesions with Plasmonic Scattering Microscopy

Cell adhesion plays a critical role in cell communication, cell migration, cell proliferation, and integration of medical implants with tissues. Focal adhesions physically link the cell cytoskeleton to the extracellular matrix, but it remains challenging to image single focal adhesions directly. Here, we show that plasmonic scattering microscopy (PSM) can directly image the single focal adhesions in a label-free, real-time, and non-invasive manner with sub-micrometer spatial resolution. PSM is developed based on surface plasmon resonance (SPR) microscopy, and the evanescent illumination makes it immune to the interference of intracellular structures. Unlike the conventional SPR microscopy, PSM can provide a high signal-to-noise ratio and sub-micrometer spatial resolution for imaging the analytes with size down to a single-molecule level, thus allowing both the super-resolution lateral localization for measuring the nanoscale displacement and precise tracking of vertical distances between the analyte centroid and the sensor surface for analysis of free-energy profiles. PSM imaging of the RBL-2H3 cell with temporal resolution down to microseconds shows that the focal adhesions have random diffusion behaviors in addition to their directional movements during the antibody-mediated activation process. The free-energy mapping also shows a similar movement tendency, indicating that the cell may change its morphology upon varying the binding conditions of adhesive structures. PSM provides insights into the individual focal adhesion activities and can also serve as a promising tool for investigating the cell/surface interactions, such as cell capture and detection and tissue adhesive materials screening.

Aetiology of tinea capitis in China: A multicentre prospective study

BACKGROUND

Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time.

OBJECTIVES

This study aimed to clarify the current epidemiological characteristics and pathogen spectrum of tinea capitis in China.

METHODS

A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. The pathogens were further identified by morphology or molecular sequencing when necessary in the central laboratory.

RESULTS

Among all enrolled patients, 74.1% of the cases were 2- to 8-year-olds. The children with tinea capitis were mainly boys (56.2%) and more likely to have an animal contact history (57.4% vs. 35.3%, P = 0.012) and zoophilic dermatophyte infection (73.5%). The adults were mainly females (83.3%) and more likely to have anthropophilic agent infection (53.5%). The most common pathogen was zoophilic Microsporum canis (354, 65.2%), followed by anthropophilic Trichophyton violaceum (74, 13.6%). In contrast to the eastern, western and northeastern regions where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69.2%, P < 0.0001), where the patients had the most tinea at other sites (20.3%) and dermatophytosis contact (25.9%) with the least animal contact (38.8%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang Province.

CONCLUSIONS

Boys aged approximately 5 years were mainly affected. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.

[Effect of splenectomy on the risk of hepatocellular carcinoma development among patients with liver cirrhosis and portal hypertension: a multi-institutional cohort study]

Objective: To identify whether splenectomy for treatment of hypersplenism has any impact on development of hepatocellular carcinoma(HCC) among patients with liver cirrhosis and hepatitis. Methods: Patients who underwent splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension between January 2008 and December 2012 were included from seven hospitals in China, whereas patients receiving medication treatments for liver cirrhosis and portal hypertension (non-splenectomy) at the same time period among the seven hospitals were included as control groups. In the splenectomy group, all the patients received open or laparoscopic splenectomy with or without pericardial devascularization. In contrast, patients in the control group were treated conservatively for liver cirrhosis and portal hypertension with medicines (non-splenectomy) with no invasive treatments, such as transjugular intrahepatic portosystemic shunt, splenectomy or liver transplantation before HCC development. All the patients were routinely screened for HCC development with abdominal ultrasound, liver function and alpha-fetoprotein every 3 to 6 months. To minimize the selection bias, propensity score matching (PSM) was used to match the baseline data of patients among splenectomy versus non-splenectomy groups. The Kaplan-Meier method was used to calculate the overall survival and cumulative incidence of HCC development, and the Log-rank test was used to compare the survival or disease rates between the two groups. Univariate and Cox proportional hazard regression models were used to analyze the potential risk factors associated with development of HCC. Results: A total of 871 patients with liver cirrhosis and hypertension were included synchronously from 7 tertiary hospitals. Among them, 407 patients had a history of splenectomy for hypersplenism (splenectomy group), whereas 464 patients who received medical treatment but not splenectomy (non-splenectomy group). After PSM,233 pairs of patients were matched in adjusted cohorts. The cumulative incidence of HCC diagnosis at 1,3,5 and 7 years were 1%,6%,7% and 15% in the splenectomy group, which was significantly lower than 1%,6%,15% and 23% in the non-splenectomy group (HR=0.53,95%CI:0.31 to 0.91,P=0.028). On multivariable analysis, splenectomy was independently associated with decreased risk of HCC development (HR=0.55,95%CI:0.32 to 0.95,P=0.031). The cumulative survival rates of all the patients at 1,3,5,and 7 years were 100%,97%,91%,86% in the splenectomy group,which was similar with that of 100%,97%,92%,84% in the non-splenectomy group (P=0.899). In total,49 patients (12.0%) among splenectomy group and 75 patients (16.2%) in non-splenectomy group developed HCC during the study period, respectively. Compared to patients in non-splenectomy group, patients who developed HCC after splenectomy were unlikely to receive curative resection for HCC (12.2% vs. 33.3%,χ²=7.029, P=0.008). Conclusion: Splenectomy for treatment of hypersplenism may decrease the risk of HCC development among patients with liver cirrhosis and portal hypertension.

Plasmonic Imaging of Electrochemical Reactions at Individual Prussian Blue Nanoparticles

Prussian blue is an iron-cyanide-based pigment steadily becoming a widely used electrochemical sensor in detecting hydrogen peroxide at low concentration levels. Prussian blue nanoparticles (PBNPs) have been extensively studied using traditional ensemble methods, which only provide averaged information. Investigating PBNPs at a single entity level is paramount for correlating the electrochemical activities to particle structures and will shed light on the major factors governing the catalyst activity of these nanoparticles. Here we report on using plasmonic electrochemical microscopy (PEM) to study the electrochemistry of PBNPs at the individual nanoparticle level. First, two types of PBNPs were synthesized; type I synthesized with double precursors method and type II synthesized with polyvinylpyrrolidone (PVP) assisted single precursor method. Second, both PBNPs types were compared on their electrochemical reduction to form Prussian white, and the effect from the different particle structures was investigated. Type I PBNPs provided better PEM sensitivity and were used to study the catalytic reduction of hydrogen peroxide. Progressively decreasing plasmonic signals with respect to increasing hydrogen peroxide concentration were observed, demonstrating the capability of sensing hydrogen peroxide at a single nanoparticle level utilizing this optical imaging technique.

Quantification of Single-Molecule Protein Binding Kinetics in Complex Media with Prism-Coupled Plasmonic Scattering Imaging

Measuring molecular binding is critical for understanding molecular-scale biological processes and screening drugs. Label-free detection technologies, such as surface plasmon resonance (SPR), have been developed for analyzing analytes in their natural forms. However, the specificity of these methods is solely relying on surface chemistry and has often nonspecific binding issues when working with samples in complex media. Herein, we show that single-molecule-based measurement can distinct specific and nonspecific binding processes by quantifying the mass and binding dynamics of individual-bound analyte molecules, thus allowing the binding kinetic analysis in complex media such as serum. In addition, this single-molecule imaging is realized in a commonly used Kretschmann prism-coupled SPR system, thus providing a convenient solution to realize high-resolution imaging on widely used prism-coupled SPR systems.

124 Perceived Quality of End-Of-Life Communication Provided by Healthcare Professionals Among Frail Older Chinese Patients

Introduction

Better communications among the patient, their family, and healthcare providers can enable a shared understanding on patient’s end-of-life (EOL) care preferences. Discussion about death-related issue however has been thought to be taboo among Chinese people. This study aims to explore perceived quality of EOL communication provided by healthcare professionals (HCPs) among frail older Chinese patients.

Method

Frail older patients were recruited from a medical ward of a public hospital for a randomized controlled trial of the effectiveness of a nurse-led advance care planning. Participants completed a baseline questionnaire including the 7-item Quality of Communication (QOC) Questionnaire which measures perceived quality of EOL communication provided by HCPs (0 “The worst or none happened” to 10 “The best”). Bivariate analyses examined associated factors of QOC.

Results

Between December 2018 and January 2020, 105 participants were recruited and have completed the QOC. Their mean age was 80 years old (SD = 7.1), and 74% (n = 78) reported had received some formal education. A total of 95 participants (91%) responded “0” to all the 7 items in QOC (poor QOC group). For individual QOC item, all participants scored “0” in 4 items, 99 scored “0” in Item 1 “Talking about details if you got sicker”, 104 scored “0” in Item 2 “Talking about how long you might have to live”, and 101 scored “0” in Item 7 “Respecting your spiritual or religious beliefs”. Participants with “0” score in QOC reported a significant lower mean level in certainty regarding decision-making in EOL preferences (1.2 ± 1.6 vs. 2.3 ± 1.8, p = 0.039).

Conclusion

Occurrence of talking about EOL care with frail older Chinese patients by HCPs was rare, and the quality of EOL communication associated with decision-making certainty regarding EOL preferences. Training of initiation of EOL discussions and improve communication skills for HCPs is essential. Funding: RGC, HKSAR, China (PolyU14162617H).

Simultaneous Imaging of Single Protein Size, Charge, and Binding Using A Protein Oscillation Approach

Electrophoresis and Western blot are important tools in protein research for detection and identification of proteins. These traditional techniques separate the proteins based on size and charge differences and identify the proteins by antibody binding. Over the past decade, the emergence of single-molecule techniques has shown great potential in improving the resolution of the traditional protein analysis methods to the single-molecule level. However, such single-molecule techniques measure either size or charge, and it is challenging to measure both at the same time. Recently, we have developed a single-molecule approach to address this problem. We tether the single proteins to a surface with a polymer linker and drive them into oscillation with an electric field. By tracking the electromechanical response of the proteins to the field using an optical imaging method, the size and charge can be obtained simultaneously. Binding of antibodies or ions to the tethered protein also changes the size and charge, which allows us to probe the interactions. This protocol includes fabrication of protein oscillators, configuration of the optical detection system, and analysis of the oscillation signal for quantification of protein size and charge. We wish this protocol will enable researchers to perform comprehensive single-protein analysis on a single platform.

[Analysis of treatment response and prognostic factors of T-LBL patients treated with pediatric-like ALL therapy following HSCT]

目的

探讨经急性淋巴细胞白血病（ALL）儿童方案治疗达到完全缓解（CR）和部分缓解（PR）的T淋巴母细胞淋巴瘤（T-LBL）患者应用造血干细胞移植巩固治疗的疗效及预后因素。

方法

收集2013年1月至2017年1月于唐都医院血液病中心接受治疗的T-LBL患者的临床资料，将达到CR或PR的患者纳入研究，进行回顾性分析。

结果

①48例患者接受了ALL儿童方案治疗，经2个疗程的诱导化疗后39例达CR，9例达PR。其中接受自体造血干细胞移植（auto-HSCT）者14例，接受异基因造血干细胞移植（allo-HSCT）者7例，21例患者移植后造血功能均顺利重建。②中位随访时间31（9～16）个月。3年总生存（OS）率为61.0%（95% CI 53.7%～68.3%），3年无进展生存（PFS）率为54.8%（95% CI 47.1%～62.2%）。③移植组和未移植组3年OS率分别为84.7%和42.8%（P＝0.006），两组3年PFS率分别为75.4%和38.9%（P＝0.004）。④auto-HSCT组与allo-HSCT组患者的OS率、PFS率差异均无统计学意义（P值分别为0.320、0.597）。⑤骨髓侵犯、未接受造血干细胞移植是影响患者长期预后的独立危险因素［ HR＝5.804（95% CI 1.140～29.549），P＝0.034；HR＝5.871（95% CI 1.711～20.140），P＝0.005］。

结论

ALL儿童方案化疗序贯造血干细胞移植治疗T-LBL疗效确切，安全性好。auto-HSCT与allo-HSCT患者的OS率及PFS率差异均无统计学意义。骨髓侵犯、未接受造血干细胞移植是影响T-LBL患者长期预后的独立危险因素。

[Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project]

OBJECTIVE

To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project.

METHODS

The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019.

RESULTS

A total area of 235.42 hm² were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project.

CONCLUSIONS

Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by "land in winter and water in summer" has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

Roles of entropic and solvent damping forces in the dynamics of polymer tethered nanoparticles and implications for single molecule sensing

Tethering a particle to a surface with a single molecule allows detection of the molecule and analysis of molecular conformations and interactions.

Tethering a particle to a surface with a single molecule allows detection of the molecule and analysis of molecular conformations and interactions. Understanding the dynamics of the system is critical to all applications. Here we present a plasmonic imaging study of two important forces that govern the dynamics. One is entropic force arising from the conformational change of the molecular tether, and the other is solvent damping on the particle and the molecule. We measure the response of the particle by driving it into oscillation with an alternating electric field. By varying the field frequency, we study the dynamics on different time scales. We also vary the type of the tether molecule (DNA and polyethylene glycol), size of the particle, and viscosity of the solvent, and describe the observations with a model. The study allows us to derive a single parameter to predict the relative importance of the entropic and damping forces. The findings provide insights into single molecule studies using not only tethered particles, but also other approaches, including force spectroscopy using atomic force microscopy and nanopores.

Retirement planning: the perceptions of pre-retirement nurses within different hospitals in China

AIM

This study explored the perceptions of senior Chinese nurses working in different hospital types, about retirement planning; and compared the results from two hospitals.

BACKGROUND

A recent review indicates that nurses with inadequate retirement planning could be faced with a retirement crisis. In China, hospitals are classified into different levels, and salaries, job satisfaction and the turnover of nurses varies among these levels. These factors may also influence nurses' perceptions of retirement planning.

METHODS

In a descriptive, qualitative design, 27 semi-structured individual interviews were conducted with nurses who were between 50 and 60 years old and recruited from two hospitals in China from April to September 2018. The interviews were transcribed and analysed thematically.

FINDINGS

Four main themes emerged from the interviews, namely, the understanding of pre-retirement nurses of retirement planning, the attitudes of pre-retirement nurses towards retirement planning, factors influencing nurses' retirement planning and the retirement planning activity of nurses. Most nurses participating in this study did not know much about retirement planning, but they all agreed on its importance. We identified the influencing factors of retirement planning and several differences regarding the perceptions of nurses about retirement planning in different hospitals.

CONCLUSION

In this cohort of nurses, planning for a good retirement was thought to be important; however, their readiness for retirement and the influences around planning for retirement were varied in type and scope.

IMPLICATIONS FOR POLICY

Governments and employing hospitals should develop reasonable measures and policies to support nurses in their understanding of the benefits of retirement planning and help them to prepare for retirement. Information about retirement planning should be made available and options for planning explained. Any systematic hurdles to retirement planning should be mitigated or eliminated.

Portable Smartphone-based Colorimetric Analyzer with Enhanced Gold Nanoparticles for On-site Tests of Seafood Safety

Saxitoxin (STX) is one of the paralytic shellfish poisons (PSP) that endanger people's health. It is necessary to develop methods for the on-site rapid detection for STX in order to prevent safety accidents. An enzyme-linked immunosorbent assay (ELISA) is timesaving and effective, but it is not suitable for large-scale in-field tests due to the expensiveness of commercial ELISA kits and the bulkiness of a microtiter plate reader (MTPR). In this study, a portable smartphone-based colorimetric analyzer (SBCA) with a cost-effictive enhanced gold nanoparticle-based ELISA (EGNB-ELISA) was proposed for STX detection. In a bicinchoninic acid (BCA) protein assay (R² = 0.9939) and a glucose assay (R² = 0.9937), SBCA was shown to be in good agreement with MTPR. EGNB-ELISA had a 12.5-fold lower detection limit (0.4 ng/mL) and a lower detection range (1 - 50 ng/mL, Y = 0.4037X + 0.3564, R² = 0.9797) than the classical ELISA. The recovery rate ranged over 89.1 - 112.2%. The whole detection system, combining both homemade SBCA and ENGB-ELISA, is expected to satisfy the needs of on-site STX sample tests to guarantee seafood safety.

[Efficacy and safety study of microsurgical varicocelectomy in the treatment of non-obstructive azoospermia with varicocele]

Objective: To discuss the efficacy and safety of subinguinal microsurgical varicocelectomy in the treatment of non-obstructive azoospermia (NOA) with varicocele. Methods: The clinical data of 141 patients with NOA and varicocele who underwent subinguinal microsurgical varicocelectomy from March 2015 to June 2017 in Shanghai General Hospital was collected.One hundred and ten patients suffered from varicocele on the left side, 1 on the right side, and the rest (30 cases) were bilateral varicocele. Grade Ⅰ varicocele were found on 7 sides (the right and left side was count respectively), grade Ⅱ on 121 sides, and grade Ⅲ on 43 sides. Sperm analysis, pregnancy rate and complications were recorded after at least 6 months since operation. Results: Eleven cases were lost during the follow-up. Eighteen of the remaining 130 NOA patients processed successful sperm retrieval in post-operative semen analysis (18/130, 13.8%). Six couples(6/130, 4.6%) succeeded in natural pregnancy. Five couples (5/130, 3.8%)underwent successful pregnancy following with intracytoplasmic sperm injection(ICSI). Twenty-six out of the remaining 112 patients underwent the micro dissection testicular sperm extraction (micro-TESE), and 4 patients got a successful sperm retrieval (4/26, 15.4%). Among them, 2 couples had successful pregnancy with ICSI. Totally 2 cases of postoperative infection of incision were found. Conclusions: Microsurgical varicocelectomy had a beneficial effect on sperm quality of patients suffered from NOA with varicocele to some extent, even leading to unassisted pregnancy or avoiding micro-TESE before ICSI. Microsurgical varicocelectomy could be applied in the treatment of NOA with varicocele.

Functional Outcome after Treatment of Aggressive Tumours in the Distal Radius: Comparison between Reconstruction using Proximal Fibular Graft and Wrist Fusion

Introduction: Restoration of a functional hand is the ultimate goal following a distal radius tumour resection. The early outcomes of mobile wrist reconstruction are satisfactory; however, long-term results are unpredictable due to late wrist instability and degenerative arthritis. Our aim is to compare mobile wrist reconstruction with wrist fusion (pan-carpal fusion) in our cohort of patients.

Materials and Methods: A retrospective cohort study was performed for functional outcomes of all patients who underwent resection for distal radius tumour and treated with either fusion or reconstruction of the wrist in a single institution from years 2000-2013 with a minimum of three years follow-up.

Results: Eleven patients were included in the study, six of whom had wrist reconstruction with proximal fibula graft and the remaining five wrist fusion, with a mean follow-up of 6.3 years. The mean Musculoskeletal Tumour Society (MSTS) score was 82.78%, ranging from 70% to 93.3%. Average grip strength compared to the normal contralateral hand was 60.0% for total wrist fusion, which was better than wrist reconstruction with 58.07%. There was no difference in the functional outcome between fusion and mobile reconstruction in our study. Osteoarthritis changes and subluxation of the wrist joint were the most common findings in the long-term follow-up for this group.

Conclusion: There was no difference in the functional outcome of the long-term follow-up between the two groups.

[Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features]

Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group (n=4) and the complete left bundle branch block (CLBBB) group (n=4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P>0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, P<0.05]. Conclusion: Bundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.

Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger

On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from [Formula: see text] to [Formula: see text] kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material.

Light curves of the neutron star merger GW170817/SSS17a: Implications for r-process nucleosynthesis

On 17 August 2017, gravitational waves (GWs) were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB 170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days postmerger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in rapid neutron capture (r-process) nucleosynthesis in the universe.

Tacrolimus protects vascular endothelial cells from injuries caused by Ox-LDL by regulating endoplasmic reticulum stress

OBJECTIVE

To study the protective effect of tacrolimus on endothelial cells under the action of oxidized low-density lipoprotein (Ox-LDL), and to explore the mechanism of tacrolimus in protecting endothelial cells.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVEC) were used and they were divided into the blank group, tacrolimus group, ox-LDL injury group, and tacrolimus + ox-LDL (tacrolimus treatment) group, for treatment. The cell viability was detected via methyl thiazolyl tetrazolium (MTT) assay; the cytotoxic response was detected via lactate dehydrogenase (LDH) release assay, and the proportion of apoptotic cells was detected via flow cytometry. Moreover, the releases of superoxide dismutase (SOD), reactive oxygen species (ROS), were detected, and the expression levels of apoptosis-related molecules, and the endoplasmic reticulum stress (ERS)-related molecules were detected via polymerase chain reaction (PCR) and Western blotting.

RESULTS

Ox-LDL could significantly reduce the viability of endothelial cells, increase the cytotoxicity and induce the apoptosis, while tacrolimus could effectively reduce such a toxic effect in a dose-dependent manner (p<0.05). Also, tacrolimus could significantly reduce the oxidative stress response of cells caused by ox-LDL and the expressions of ERS-related proteins, and protect the cells from oxidative stress injury (p<0.05).

CONCLUSIONS

Tacrolimus regulates ERS of endothelial cells to reduce ox-LDL-induced injuries.

[Efficacy and safety of Rivaroxaban anticoagulant therapy in the treatment of atrial fibrillation cryoablation]

Objective: To observe the efficacy and safety of the novel oral anticoagulant Rivaroxaban for anticoagulation therapy in patients with nonvalvular atrial fibrillation (AF) during cryoablation. Methods: A total of 137 AF patients from October 2013 to December 2016 underwent cryoablation were divided into two groups according to the application of anticoagulant drugs: Rivaroxaban group (65 cases) and Heparin group (72 cases). Rivaroxaban group: oral administration of Rivaroxaban 20 mg, once a day, was started 3 days before the cryoablation, no anticoagulant was additionally added during cryoablation, the activated clotting time (ACT) was measured, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. Heparin group: oral administration of Rivaroxaban 20 mg, once a day, was stopped 24 hours before the cryoablation, heparin (100 U/kg) anticoagulation was given during cryoablation, ACT was controlled between 250 and 300 seconds, and oral administration of Rivaroxaban was continued for 3 months after cryoablation. The ACT results, the incidence of bleeding and thromboembolic events between the two groups were compared. Results: The ACT result between the two groups were with statistically significance[(110±16) vs (323±61) seconds, P=0.000)]. The bleeding events for Rivaroxaban group were two cases of local hematoma of the femoral vein puncture site, with the incidence rate of 3.1%(2/65); Heparin group were two cases of local hematoma of the femoral vein puncture site, and one case of epistaxis, with the incidence rate of 4.2%(3/72), with no statistical significance(P=0.549) between the two groups. No thromboembolic event occurred in the Rivaroxaban group, one cerebellar thromboembolic event occurred in the Heparin group during anticoagulant bridging phase after cryoablation. Conclusion: Rivaroxaban is safe and effective for anticoagulation therapy in patients with atrial fibrillation cryoablation.

[Correlation between anatomical factors of spermatic vessels and varicocele]

Objective: To analyze the correlation between anatomy of spermatic vessels and varicocele, providing reference for the preoperative assessment and treatment of varicocele. Methods: A total of 156 patients who underwent microsurgical left subinguinal varicocelectomy at Shanghai General Hospital between May 2015 and July 2016 were included in this study. The severity of varicocele and number of spermatic vessels detected in operations were recorded. According to the number of internal spermatic arteries (ISAs), the patients were divided into three groups: single-ISA group (55 cases), double-ISAs group (63 cases) and multi-ISAs group (38 cases), to analyze the correlation among spermatic vessels and to compare varicocele grade, the volume of testes, the parameter of semen analysis, serum reproductive hormone, surgery time, and hospital stay among the three groups. Results: The number of ISAs was positively correlated with the ipsilateral internal spermatic veins (ISVs) (r=0.210; P=0.008)and lymphatic vessels (r=0.224; P=0.005); the number of lymphatic vessels was positively correlated with the ipsilateral gubernacular veins (r=0.172; P=0.032)and ISVs (r=0.296; P=0.000) . The number of ISVs in the multi-ISAs group (10.58±4.28) was significantly larger than that in the single-ISA group (8.22±3.10, P=0.003). The number of lymphatic vessels in the multi-ISAs group(4.11±1.90)was also significantly larger than that in the double-ISA group(3.76±1.40, P=0.020) and the single-ISA group(3.13±1.52, P=0.007). The number of ISVs in grade 2 varicocele patients (9.74±3.90) was significantly higher than that in grade 3 varicocele patients (8.33±3.10, P=0.013). No significant differences in varicocele grade, change of pre- and post-operative semen analysis, serum reproductive hormone, the volume of ipsilateral testes, surgery time, and hospital stay were observed among the three groups. Conclusions: There is a correlation among various kinds of spermatic vessels. Patients with grade 2 varicocele, especially who have multiple ISAs, are likely to have more ISVs and lymphatic vessels. For these patients, surgeons should pay more attention to protect spermatic arteries and lymphatics carefully while ligating varicose veins completely to prevent recurrence and complications.

Effect of whey protein on blood lipid profiles: a meta-analysis of randomized controlled trials

Previous studies have suggested that whey supplementation may have beneficial effects on lipid profiles, although results were inconsistent. A literature search was performed in March 2015 for randomized controlled trials observing the effects of whey protein and its derivatives on circulating levels of triacylglycerol (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). A meta-analysis was subsequently conducted. The meta-analysis results of 13 trials showed that whey supplementation significantly reduced the circulating TG level by 0.11 mmol/l (95% CI: -0.21, 0 mmol/l), whereas the whey protein had no effects on circulating TC (-0.11 mmol/l, 95% CI: -0.27, 0.05 mmol/l), LDL-C (-0.08 mmol/l, 95% CI: -0.23, 0.07 mmol/l) and HDL-C (0.01 mmol/l, 95% CI: -0.04, 0.05 mmol/l). Subgroup analysis showed that significant TG reduction disappeared in participants with low body mass index, low supplemental whey dose or under exercise training/energy restriction during the trial. No evidence of heterogeneity across studies and publication bias was observed. In conclusion, our findings demonstrated that the effects of whey protein supplementation were modest, with an overall lowering effect on TG but no effect on TC, LDL-C and HDL-C.