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Introduction: Peptide drugs are highly regarded for their therapeutic versatility, safety, and efficacy in treating conditions like cancer, hepatitis, and diabetes. Animal-derived Traditional Chinese Medicines (TCMs) are promising peptide sources, often outperforming plant-based alternatives. The therapeutic effects of leeches, earthworms, and Eupolyphaga sinensis Walkers in thrombosis and blood stasis have been clinically validated, with anticoagulant peptides as key components; however, their pharmacological mechanisms remain unclear. This review categorizes and summarizes anticoagulant peptides from animal-derived TCMs by species. Methods: This study explores the important role of anticoagulant peptides from animal-sourced medicine in treating thrombosis-related diseases. A literature search using keywords like “anticoagulant peptides,” “leech peptides,” and “earthworm peptides” yielded over 120 articles, of which 85 were selected. Priority was given to studies from the past 20 years, while significant historical research was also noted. Articles lacking specific information on the animal sources of these peptides were excluded. Data were obtained from a diverse range of references, including both ancient and modern texts, the Chinese Pharmacopoeia, Web of Science, PubMed, ScienceDirect, Google Scholar, Springer, and CNKI. Conclusion: This study reviews six promising animal-derived anticoagulant drugs currently in clinical use: leeches, earthworms, scorpions, Eupolyphaga sinensis Walkers, and centipedes. Key peptides under development include hirudin (Hirudo nipponica), WP-30 (Whitmania pigra), Lomburkinase (Eisenia foetida). These peptides exhibit potent anticoagulant, antiplatelet, and anti-inflammatory effects, rendering them valuable in the treatment of cardiovascular diseases, stroke, amenorrhea, cerebral thrombosis, and atherosclerosis. Discussion: This study critically evaluates the therapeutic mechanisms of anticoagulant peptides in animal-sourced medicines, emphasizing the potential of peptide-based therapies across different strains of the same species for traditional Chinese medicine and modern clinical use. Despite promising potential, challenges such as low bioavailability, difficulties in peptide identification, pharmacological evaluation, and toxicity assessment persist. Addressing these issues will facilitate deeper exploration and development of peptide-based therapies.

Abstract Background Subjective well-being (SWB) plays an essential role in general health. Although beneficial effects of selected micronutrients and foods on SWB have been reported, they do not reflect the impact of the habitual diet on SWB. Therefore, the purpose of this study is to investigate the association between adherence to the Chinese Dietary Guidelines (CDG) with SWB. Methods This study combined a cross-sectional survey and a daily diary investigation. The cross-sectional survey was conducted on 1,433 students from 8 universities in southern China between October and November 2020. The daily diary investigation was conducted in November 2022, collecting 10-day daily data from 115 students at two universities in southern China over ten consecutive days, resulting in 1,020 valid matched daily responses. Adherence to the CDG was assessed by the China Prime Diet Quality Score (CPDQS), SWB was measured by the Index of Well-being (IWB) and the Affect Valuation Index (AVI). Correlation analysis, multiple regression analyses, and hierarchical regression were conducted to examine the associations of adherence to the CDG with its components, and SWB. Results The cross-sectional survey revealed significant predictors of SWB, including adherence to the CDG (β = 0.24, p

ABSTRACTRecently discovered tet(X) gene variants have provided new insights into microbial antibiotic resistance mechanisms and their potential consequences for public health. This study focused on detection, analysis, and characterization of Tet(X4)-positive Enterobacterales from the gut microbiota of a healthy cohort of individuals in Singapore using cultivation-dependent and cultivation-independent approaches. Twelve Tet(X4)-positive Enterobacterales strains that were previously obtained from the cohort were fully genome-sequenced and comparatively analyzed. A metagenomic sequencing (MS) data set of the same samples was mined for contigs that harbored the tet(X4) resistance gene. The sequences of tet(X4)-containing contigs and plasmids sequences were compared. The presence of the resistance genes floR and estT (previously annotated as catD) was detected in the same cassette in 10 and 12 out of the 12 tet(X4)-carrying plasmids, respectively. MS detected tet(X4)-containing contigs in 2 out of the 109 subjects, while cultivation-dependent analysis previously reported a prevalence of 10.1%. The tet(X4)-containing sequences assembled from MS data are relatively short (~14 to 33 kb) but show high similarity to the respective plasmid sequences of the isolates. Our findings show that MS can complement efforts in the surveillance of antibiotic resistance genes for clinical samples, while it has a lower sensitivity than a cultivation-based method when the target organism has a low abundance. Further optimization is required if MS is to be utilized in antibiotic resistance surveillance.IMPORTANCEThe global rise in antibiotic resistance makes it necessary to develop and apply new approaches to detect and monitor the prevalence of antibiotic resistance genes in human populations. In this regard, of particular interest are resistances against last-resort antibiotics, such as tigecycline. In this study, we show that metagenomic sequencing can help to detect high abundance of the tigecycline resistance gene tet(X4) in fecal samples from a cohort of healthy human subjects. However, cultivation-based approaches currently remain the most reliable and cost-effective method for detection of antibiotic-resistant bacteria.

In this study, heat-moisture treatment (HMT) at 60 °C and 65 °C for 12 h and 18 h was applied to harvested raw paddy rice (Oryza sativa L. cv. Toyomeki), and changes in the quality characteristics and starch hydrolysis during simulated gastrointestinal digestion were investigated. The surface color of the treated rice grains was mainly caused by the period of HMT rather than the heating temperature. HMT at mild temperatures caused a minor change with no significant effect in the total starch content of the treated rice, as well as the moisture content and firmness of the cooked rice (P > 0.05). However, the resistant starch content increased with increasing HMT temperature and time, and a significant difference was found between the control and the treated rice subjected at 65 °C. The mild HMT also promoted the reduction trend of starch hydrolysis for the intact cooked rice grain, which could have health benefits. Thus, the mild HMT of raw paddy rice could be regarded as a profitable technique modifying the digestibility of cooked rice but maintaining rice sensory characteristics.

Abstract The catalytic performance of metal–organic frameworks (MOFs) in Li‐S batteries is significantly hindered by unsuitable pore size, low conductivity, and large steric contact hindrance between the catalytic site and lithium polysulfide (LPSs). Herein, the smallest π‐conjugated hexaaminobenzene (HAB) as linker and Ni(II) ions as skeletal node are in situ assembled into high crystallinity Ni‐HAB 2D conductive MOFs with dense Ni‐N4 units via dsp2 hybridization on the surface of carbon nanotube (CNT), fabricating Ni‐HAB@CNT as separator modified layer in Li‐S batteries. As‐obtained unique π‐d conjugated Ni‐HAB nanostructure features ordered micropores with suitable pore size (≈8 Å) induced by HAB ligands, which can cooperate with dense Ni‐N4 chemisorption sites to effectively suppress the shuttle effect. Meanwhile, the conversion kinetics of LPSs is significantly accelerated owing to the small steric contact hindrance and increased delocalized electron density endued by the planar tetracoordinate structure. Consequently, the Li‐S battery with Ni‐HAB@CNT modified separator achieves an areal capacity of 6.29 mAh cm−2 at high sulfur loading of 6.5 mg cm−2 under electrolyte/sulfur ratio of 5 µL mg−1. Moreover, Li‐S single‐electrode pouch cells with modified separators deliver a high reversible capacity of 791 mAh g−1 after 50 cycles at 0.1 C with electrolyte/sulfur ratio of 6 µL mg−1.

BackgroundThe use of heating and ventilation air conditioning (HVAC) in public places is conducive to improving indoor air quality and increasing the users comfort level. However, HVAC may also become potential carriers of indoor airborne microbial contamination.ObjectiveTo understand the characteristics of microbial pollution and distribution of related pathogenic microorganisms in HVAC of star-rated hotels, and to provide a basis for effective control of such pollution.MethodsAccording to the requirements of the Hygienic specification of central air conditioning ventilation system in public buildings (WS 394-2012), two sets of HVAC in two star-rated hotels (A and B, inaugurated in 2002 and 1998, respectively) in the central area of Shanghai were randomly selected on September 9, 2020 for the hygienic evaluation of microorganisms in the air supply and respirable particulate matter (PM10) in the air supply, dust accumulation and microorganisms on the inner surface of the ducts, as well as Legionella pneumophila in cooling water and condensate water. At the same time, 3 samples from the inner surface of ducts, 1 sample from the surface of the filter, 1 sample from the condensate, and 1 sample from the cooling water were collected from each set of HVAC, a total of 12 sample from 2 sets of HVAC, for Illumina HiSeq metagenomic sequencing，and the samples are divided into 3 groups according to their types: duct group, filter group, and water sample group. The α-diversity indices (Shannon index, Simpson index, Chao1 index, ACE index, and goods_coverage index) were calculated to reflect the microbial community composition; and the β-diversity of the three groups were studied by principal component analysis to determine the similarity of the microbial communities.ResultsThe maximum total number of bacteria and fungi in the air supply of the HVAC were 1158 CFU·m−3 and 344 CFU·m−3 for Hotel A respectively; and 2000 CFU·m−3 and 532 CFU·m−3 for Botel B respectively. β-hemolytic streptococci were negative in all samples; the respirable particulate matter, microorganisms and dust accumulation on the inner surface of air ducts, Legionella pneumophila IN cooling water and condensate samples all met the standards. The results of Illumina HiSeq sequencing showed that a total of 17322 microorganisms were reported in the 12 samples, with bacterial microbiota accounting for 97.31% of the classified genes and the remaining 2.69% were from fungi, viruses, and parasites. At the species level, Staphylococcus epidermidis, Pseudomonas, Alternaria, and Malassezia were the dominant microbial taxa measured in this survey. The results of α-diversity analysis showed that the values of Shannon index, Simpson index, and Chao1 index for the three groups of samples were duct > filter > water sample. The goods coverage indices of all sample groups s were close to 1. The principal component analysis showed that the contributions of two principal components were 19.27% and 14.25%, respectively, in which the samples of the filter and duct groups were better clustered into one category.ConclusionThe overall hygiene conditions of the two hotels are good, except for the serious microbial contamination in the air supply of HVAC. Metagenomic sequencing reveals complex microbial communities of HVAC, including bacteria, fungi, viruses, and parasites. The species composition vary by sample groups, particularly the species compositions of the samples from filters and ducts are close and dominated by pathogenic microorganisms of human origin, suggesting that the potential biosafety hazards of HVAC should not be ignored.

Reference genomes for gut microbiomes help unravel microbial “dark matter” and serve as valuable resource for disease-focused studies. Here, the authors perform short and long read metagenomics and metagenome-assembled genomes analyses to profile the gut microbiome of Southeast Asian populations, revealing significant species and strain-level diversity, with thousands of previously uncharacterized biosynthetic gene clusters.

ABSTRACT Streptococcus gallolyticus subsp. gallolyticus (SGG) is an opportunistic bacterial pathogen strongly associated with colorectal cancer. Here, through comparative genomics analysis, we demonstrated that the genetic locus encoding the type VIIb secretion system (T7SSb) machinery is uniquely present in SGG in two different arrangements. SGG UCN34 carrying the most prevalent T7SSb genetic arrangement was chosen as the reference strain. To identify the effectors secreted by this secretion system, we inactivated the essC gene encoding the motor of this machinery. A comparison of the proteins secreted by UCN34 wild type and its isogenic ΔessC mutant revealed six T7SSb effector proteins, including the expected WXG effector EsxA and three LXG-containing proteins. In this work, we characterized an LXG-family toxin named herein TelE promoting the loss of membrane integrity. Seven homologs of TelE harboring a conserved glycine zipper motif at the C terminus were identified in different SGG isolates. Scanning mutagenesis of this motif showed that the glycine residue at position 470 was crucial for TelE membrane destabilization activity. TelE activity was antagonized by a small protein TipE belonging to the DUF5085 family. Overall, we report herein a unique SGG T7SSb effector exhibiting a toxic activity against nonimmune bacteria. IMPORTANCE In this study, 38 clinical isolates of Streptococcus gallolyticus subsp. gallolyticus (SGG) were sequenced and a genetic locus encoding the type VIIb secretion system (T7SSb) was found conserved and absent from 16 genomes of the closely related S. gallolyticus subsp. pasteurianus (SGP). The T7SSb is a bona fide pathogenicity island. Here, we report that the model organism SGG strain UCN34 secretes six T7SSb effectors. One of the six effectors named TelE displayed a strong toxicity when overexpressed in Escherichia coli. Our results indicate that TelE is probably a pore-forming toxin whose activity can be antagonized by a specific immunity protein named TipE. Overall, we report a unique toxin-immunity protein pair and our data expand the range of effectors secreted through T7SSb.

Despite ongoing efforts in cardiovascular research, the acquisition of high-resolution and high-speed images for the purpose of assessing cardiac contraction remains challenging. Light-sheet fluorescence microscopy (LSFM) offers superior spatiotemporal resolution and minimal photodamage, providing an indispensable opportunity for the in vivo study of cardiac micro-structure and contractile function in zebrafish larvae. To track the myocardial architecture and contractility, we have developed an imaging strategy ranging from LSFM system construction, retrospective synchronization, single cell tracking, to user-directed virtual reality (VR) analysis. Our system enables the four-dimensional (4D) investigation of individual cardiomyocytes across the entire atrium and ventricle during multiple cardiac cycles in a zebrafish larva at the cellular resolution. To enhance the throughput of our model reconstruction and assessment, we have developed a parallel computing-assisted algorithm for 4D synchronization, resulting in a nearly tenfold enhancement of reconstruction efficiency. The machine learning-based nuclei segmentation and VR-based interaction further allow us to quantify cellular dynamics in the myocardium from end-systole to end-diastole. Collectively, our strategy facilitates noninvasive cardiac imaging and user-directed data interpretation with improved efficiency and accuracy, holding great promise to characterize functional changes and regional mechanics at the single cell level during cardiac development and regeneration.

For China to achieve carbon neutrality by 2060, the profound transformation from high-carbon to low-carbon and carbon-free energy sources is required for the energy supply and demand structure. In the future, the gas consumption will grow in large scale in China. It is estimated that the natural gas consumption in China will be about 6 000×108 m3 by 2030 and 6 500×108 m3 to 7 500×108 m3 by 2060. Due to the impact of the resource reserves, the capability to acquiring international resources, the safety of import channels and other factors on China's natural gas, it is necessary to build underground gas storages in large scale to ensure the growth of China's natural gas consumption. From the perspective of natural gas consumption safety, the underground gas storages with a gas storage capacity of 1 200×108 m3 to 1 300×108 m3 should be constructed, so as to meet the requirements for peak sheaving of natural gas in China and maintain the strategic reserves required. At present, the working gas capacity of China's underground gas storages is only about 150×108 m3, and it is necessary to further expand the field of storage construction to form the space layout of "1+3+N" gas storage base. In the process of China's energy transition, the related technologies of gas storage will be deeply integrated with the carbon storage, hydrogen storage, helium storage, compressed gas storage and other technologies in the future, for the purpose of maximizing the role of underground gas storages in energy field and facilitating to realize the strategic objective of carbon neutrality.

Heat moisture treatment is safe and non-chemical use method for modifying physicochemical properties and digestibility of starch. Slow starch digestion in rice product would provide numerous health benefits for the consumers. This study investigated the heat-moisture treatment to the raw paddy rice at 60 and 80 °C for 4 and 24 h, and their effects on the attributes of cooked rice. The firmness, adhesiveness, starch hydrolysis and morphological changes during in vitro digestion were examined. Results showed that heat-moisture treatment to raw paddy rice for 24 h significantly reduced the moisture content and could increase the total starch content of the rice grain. The apparent amylose content ranged from 23.83% to 25.65% at the variation in the values between treated and untreated rice. Enhancement in the firmness and reduction in the starch hydrolysis was found in rice treated by longer heating time of 24 h. Meanwhile, the adhesiveness of cooked rice was decreased when increasing the heating temperature. The morphological observation showed that the treated rice exhibited a honey-comb-like structure during simulated gastric digestion, while the untreated rice displayed a non-uniform structure. Noteworthy, the porous structure observed in all digested rice grains during simulated small intestinal digestion could favor the starch hydrolysis. This study showed that the heat-moisture treatment to the raw paddy rice at certain conditions obviously influenced the attributes of cooked rice, especially on the starch hydrolysis, which would provide a fundamental knowledge to enable development and improvement of slow digestion rice products.

BackgroundThe recent focus on the critical setting, especially with the COVID-19 pandemic, has highlighted the need for minimizing contact-based care and increasing robotic use. Robotics is a rising field in the context of health care, and we sought to evaluate the use of robots in critical care settings. ObjectiveAlthough robotic presence is prevalent in the surgical setting, its role in critical care has not been well established. We aimed to examine the uses and limitations of robots for patients who are critically ill. MethodsThis systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. MEDLINE, Embase, IEEE Xplore, and ACM Library were searched from their inception to December 23, 2021. Included studies involved patients requiring critical care, both in intensive care units or high-dependency units, or settings that required critical care procedures (eg, intubation and cardiopulmonary resuscitation). Randomized trials and observational studies were included. ResultsA total of 33 studies were included. The greatest application of robots in the intensive care unit was in the field of telepresence, whereby robots proved advantageous in providing a reduced response time, earlier intervention, and lower mortality rates. Challenges of telepresence included regulatory and financial barriers. In therapy and stroke rehabilitation, robots achieved superior clinical outcomes safely. Robotic use in patient evaluation and assessment was mainly through ultrasound evaluation, obtaining satisfactory to superior results with the added benefits of remote assessment, time savings, and increased efficiency. Robots in drug dispensing and delivery increased efficiency and generated cost savings. All the robots had technological limitations and hidden costs. ConclusionsOverall, our results show that robotic use in critical care settings is a beneficial, effective, and well-received intervention that delivers significant benefits to patients, staff, and hospitals. Looking ahead, it is necessary to form strong ethical and legislative frameworks and overcome various regulatory and financial barriers. Trial RegistrationPROSPERO International Prospective Register of Systematic Reviews CRD42021234162; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=234162

Mechano-responsive signaling pathways enable blood vessels within a connected network to structurally adapt to partition of blood flow between organ systems. Wall shear stress (WSS) modulates endothelial cell proliferation and arteriovenous specification. Here, we study vascular regeneration in a zebrafish model by using tail amputation to disrupt the embryonic circulatory loop (ECL) at 3 days post fertilization (dpf). We observed a local increase in blood flow and peak WSS in the Segmental Artery (SeA) immediately adjacent to the amputation site. By manipulating blood flow and WSS via changes in blood viscosity and myocardial contractility, we show that the angiogenic Notch-ephrinb2 cascade is hemodynamically activated in the SeA to guide arteriogenesis and network reconnection. Taken together, ECL amputation induces changes in microvascular topology to partition blood flow and increase WSS-mediated Notch-ephrinb2 pathway, promoting new vascular arterial loop formation and restoring microcirculation.

Molecular imaging along with 3-dimensional (3-D) or 4-D (3-D spatial + 1-D temporal) visualization is widely used in clinical diagnosis and surgical planning. However, the pre-defined perspective and confined manipulation limit the in-depth exploration and analysis in 3-D/4-D. To overcome this obstacle, we utilized virtual reality (VR) to interact with CT images of the cardiopulmonary system in a 3-D immersive environment. We implemented manipulative functionalities into the VR environment that altered the cardiopulmonary models to interactively generate new data analysis perspectives. We successfully sliced a CT cardiac model showing in-depth surface visualizations of the ventricles and atria. Our customized framework enables enhanced data interpretation interactivity of CT images and establishes a user-directed manipulative VR platform derived from imaging results for remote medical practices including training, education, and investigation.

Deep neural networks have become the mainstream approach for analyzing and interpreting histology images. In this study, we established and validated an interpretable DNN model to assess endomyocardial biopsy (EMB) data of patients with myocardial injury. Deep learning models were used to extract features and classify EMB histopathological images of heart failure cases diagnosed with either ischemic cardiomyopathy or idiopathic dilated cardiomyopathy and non-failing cases (organ donors without a history of heart failure). We utilized the gradient-weighted class activation mapping (Grad-CAM) technique to emphasize injured regions, providing an entry point to assess the dominant morphology in the process of a comprehensive evaluation. To visualize clustered regions of interest (ROI), we utilized uniform manifold approximation and projection (UMAP) embedding for dimension reduction. We further implemented a multi-model ensemble mechanism to improve the quantitative metric (area under the receiver operating characteristic curve, AUC) to 0.985 and 0.992 on ROI-level and case-level, respectively, outperforming the achievement of 0.971 ± 0.017 and 0.981 ± 0.020 based on the sub-models. Collectively, this new methodology provides a robust and interpretive framework to explore local histopathological patterns, facilitating the automatic and high-throughput quantification of cardiac EMB analysis.

China has achieved success in implementing the rural revitalization strategy and promoting the development of new urbanization. However, there are still many problems in the research and implementation on urban–rural integration development, such as insufficient research at the township level, unclear recognition of development patterns, and disconnection from land-use planning. Therefore, taking Hanchuan city in the Wuhan metropolitan area as a case study, this research constructs a comprehensive evaluation system of urban–rural integration development based on both on the current and potential level of development, and identifies the spatial characteristics and patterns in the study area. This study found that: (1) The comprehensive evaluation result of urban–rural integration development in Hanchuan City shows that a high level of development units are mainly distributed in the northeast and southwest, and gradually decreases from the northeast and southwest, indicating that towns in the central area are relatively weakly driven by the radiation of the surrounding growth poles. (2) Xiannvshan Street, Makou Town, Chenhu Town, and Xinyan Town with the highest comprehensive evaluation values were selected as the centers of urban–rural integration development in four directions. (3) Four typical patterns of urban–rural integration development, which are town gathering, agro-tourism interaction, industry-trade driven, and agricultural service, are derived by the gravity model and classification assignment method according to their respective centers. (4) According to the urban–rural integration development patterns, land-use strategies such as centralization for promoting linkage level of towns, differentiation for arranging various resources and infrastructures, and demonstration for optimization of experience to the whole area are proposed in a targeted manner. This study has important implications for the preparation and implementation of urban–rural integration development and provides effective planning guidance for promoting social equity and accessibility of facilities in the metropolitan area.

Metropolitan areas in China are not only the core spatial carriers of urbanization development but also the main generators of land use carbon emission (LUCE). However, existing research lacks comparative studies on the differential patterns and impact factors of LUCE in different stages of metropolitan areas. Therefore, this paper deeply analyzes the spatial characteristics of LUCE and the coupling coordination degree (CCD) of the economy contributive coefficient (ECC) and ecological support coefficient (ESC) in three different stages of metropolitan areas in the Yangtze River Economic Belt (YREB), China. Moreover, quantitative modelling of the impact factors of LUCE in these different stages of metropolitan areas is furtherly revealed. Results show that: (1) The more mature stage of the metropolitan area, the higher the amount of LUCE, and the more districts or counties with high carbon emissions levels are clustered. (2) At the metropolitan area scale, the more mature the metropolitan area is and the lower the CCD between ECC and ESC is, while at the finer scale, more developed counties have lower CCD. (3) Resident population, per capita GDP, and urbanization rate have good explanatory effects on carbon emissions in these three metropolitan areas; however, except for the urbanization rate, which has a negative effect on LUCE in Nanchang metropolitan area (NMA), the other two factors have positive effects on LUCE in these three metropolitan areas. This study has important implications for different stages of metropolitan areas to formulate targeted LUCE reduction policies.

Biomechanical forces intimately contribute to cardiac morphogenesis. However, volumetric imaging to investigate the cardiac mechanics with high temporal and spatial resolution remains an imaging challenge. We hereby integrated light-field microscopy (LFM) with light-sheet fluorescence microscopy (LSFM), coupled with a retrospective gating method, to simultaneously access myocardial contraction and intracardiac blood flow at 200 volumes per second. While LSFM allows for the reconstruction of the myocardial function, LFM enables instantaneous acquisition of the intracardiac blood cells traversing across the valves. We further adopted deformable image registration to quantify the ventricular wall displacement and particle tracking velocimetry to monitor intracardiac blood flow. The integration of LFM and LSFM enabled the time-dependent tracking of the individual blood cells and the differential rates of segmental wall displacement during a cardiac cycle. Taken together, we demonstrated a hybrid system, coupled with our image analysis pipeline, to simultaneously capture the myocardial wall motion with intracardiac blood flow during cardiac development.

Abstract Background Optical imaging is one of the most common, low-cost imaging tools used for investigating the tumor biological behavior in vivo. This study explores the feasibility and sensitivity of a near infrared fluorescent protein mKate2 for a long-term non-invasive tumor imaging in BALB/c nude mice, by using a low-power optical imaging system. Methods In this study, breast cancer cell line MDA-MB-435s expressing mKate2 and MDA-MB-231 expressing a dual reporter gene firefly luciferase (fLuc)-GFP were used as cell models. Tumor cells were implanted in different animal body compartments including subcutaneous, abdominal and deep tissue area and closely monitored in real-time. A simple and low-power optical imaging system was set up to image both fluorescence and bioluminescence in live animals. Results The presence of malignant tissue was further confirmed by histopathological assay. Considering its lower exposure time and no need of substrate injection, mKate2 is considered a superior choice for subcutaneous imaging compared with fLuc. On the contrary, fLuc has shown to be a better option when monitoring the tumor in a diffusive area such as abdominal cavity. Furthermore, both reporter genes have shown good stability and sensitivity for deep tissue imaging, i.e. tumor within the liver. In addition, fLuc has shown to be an excellent method for detecting tumor cells in the lung. Conclusions The combination of mKate2 and fLuc offers a superior choice for long-term non-invasive real-time investigation of tumor biological behavior in vivo.

Pseudomonas aeruginosa is an environmental microorganism that can thrive in diverse ecological niches including plants, animals, water, soil, and crude oil. It also one of the microorganism widely used in tertiary recovery of crude oil and bioremediation. However, the genomic information regarding the mechanisms of survival and adapation of this bacterium in crude oil is still limited. In this study, three Pseudomonads strains (named as IMP66, IMP67, and IMP68) isolated from crude oil were taken for whole-genome sequencing by using a hybridized PacBio and Illumina approach. The phylogeny analysis showed that the three strains were all P. aeruginosa species and clustered in clade 1, the group with PAO1 as a representitive. Subsequent comparative genomic analysis revealed a high degree of individual genomic plasticity, with a probable alkane degradation genomic island, one type I-F CRISPR-Cas system and several prophages integrated into their genomes. Nine genes encoding alkane hydroxylases (AHs) homologs were found in each strain, which might enable these strains to degrade alkane in crude oil. P. aeruginosa can produce rhamnolipids (RLs) biosurfactant to emulsify oil, which enables their survival in crude oil enviroments. Our previous report showed that IMP67 and IMP68 were high RLs producers, while IMP66 produced little RLs. Genomic analysis suggested that their RLs yield was not likely due to differences at genetic level. We then further analyzed the quorum sensing (QS) signal molecules that regulate RLs synthesis. IMP67 and IMP68 produced more N-acyl-homoserine lactones (AHLs) signal molecules than that of PAO1 and IMP66, which could explain their high RLs yield. This study provides evidence for adaptation of P. aeruginosa in crude oil and proposes the potential application of IMP67 and IMP68 in microbial-enhanced oil recovery and bioremediation.

Abstract Background Salmonella enterica subspecies enterica serovar Saintpaul (S. Saintpaul) is an important gut pathogen which causes salmonellosis worldwide. Although intestinal salmonellosis is usually self-limiting, it can be life-threatening in children, the elderlies and immunocompromised patients. Appropriate antibiotic treatment is therefore required for these patients. However, the efficacy of many antibiotics on S. enterica infections has been greatly compromised due to spreading of multidrug resistance (MDR) plasmids, which poses serious threats on public health and needs to be closely monitored. In this study, we sequenced and fully characterized an S. enterica MDR plasmid pSGB23 isolated from chicken. Results Complete genome sequence analysis revealed that S. Saintpaul strain SGB23 harbored a 254 kb megaplasmid pSGB23, which carries 11 antibiotic resistance genes responsible for resistance to 9 classes of antibiotics and quaternary ammonium compounds that are commonly used to disinfect food processing facilities. Furthermore, we found that pSGB23 carries multiple conjugative systems, which allow it to spread into other Enterobacteriaceae spp. by self-conjugation. It also harbors multiple types of replicons and plasmid maintenance and addictive systems, which explains its broad host range and stable inheritance. Conclusions We report here a novel MDR plasmid pSGB23 harboured by S. enterica. To our knowledge, it carried the greatest number of antibiotic resistance genes with the broadest range of resistance spectrum among S. enterica MDR plasmids identified so far. The isolation of pSGB23 from food sources is worrisome, while surveillance on its further spreading will be carried out based on the findings reported in this study.

During cardiac tissue formation it is unclear whether newly generated myocytes originate from cardiac progenitor cells or from pre-existing cardiomyocytes. Here, the authors use a stochastic four-colour reporter system (Rainbow) to identify the source of new cardiomyocytes during mouse development.

Abstract This study sought to develop an automated segmentation approach based on histogram analysis of raw axial images acquired by light-sheet fluorescent imaging (LSFI) to establish rapid reconstruction of the 3-D zebrafish cardiac architecture in response to doxorubicin-induced injury and repair. Input images underwent a 4-step automated image segmentation process consisting of stationary noise removal, histogram equalization, adaptive thresholding, and image fusion followed by 3-D reconstruction. We applied this method to 3-month old zebrafish injected intraperitoneally with doxorubicin followed by LSFI at 3, 30, and 60 days post-injection. We observed an initial decrease in myocardial and endocardial cavity volumes at day 3, followed by ventricular remodeling at day 30, and recovery at day 60 (P

Abstract Pacemakers have existed for decades as a means to restore cardiac electrical rhythms. However, lead-related complications have remained a clinical challenge. While market-released leadless devices have addressed some of the issues, their pacer-integrated batteries cause new health risks and functional limitations. Inductive power transfer enables wireless powering of bioelectronic devices; however, Specific Absorption Rate and size limitations reduce power efficiency for biomedical applications. We designed a remote-controlled system in which power requirements were significantly reduced via intermittent power transfer to control stimulation intervals. In parallel, the cardiac component was miniaturized to facilitate intravascular deployment into the anterior cardiac vein. Given size constraints, efficiency was optimal via a circular receiver coil wrapped into a half-cylinder with a meandering tail. The pacemaker was epicardially tested in a euthanized pig at 60 beats per minute, 2 V amplitude, and 1 ms pulse width, restoring mean arterial pressure from 0 to 37 mmHg. Power consumption was 1 mW at a range of > 3 cm with no misalignment and at 2 cm with 45° displacement misalignment, 45° x-axis angular misalignment, or 45° y-axis angular misalignment. Thus, we demonstrated a remote-controlled miniaturized pacing system with low power consumption, thereby providing a basis for the next generation of wireless implantable devices.

Abstract Blood viscosity provides the rheological basis to elucidate shear stress underlying developmental cardiac mechanics and physiology. Zebrafish is a high throughput model for developmental biology, forward-genetics, and drug discovery. The micro-scale posed an experimental challenge to measure blood viscosity. To address this challenge, a microfluidic viscometer driven by surface tension was developed to reduce the sample volume required (3μL) for rapid (500 s−1), at which the power law exponent (n) of zebrafish blood was nearly 1 behaving as a Newtonian fluid. The measured values of whole blood from the micro-channel (4.17cP) and the vacuum method (4.22cP) at 500 s−1 were closely correlated at 27 °C. A calibration curve was established for viscosity as a function of hematocrits to predict a rise and fall in viscosity during embryonic development. Thus, our rapid capillary pressure-driven micro-channel revealed the Newtonian fluid behavior of zebrafish blood at high shear rates and the dynamic viscosity during development.

Pseudomonas aeruginosa is an opportunistic pathogen that causes severe airway infections in humans. These infections are usually difficult to treat and associated with high mortality rates. While colonizing the human airways, P. aeruginosa could accumulate genetic mutations that often lead to its better adaptability to the host environment. Understanding these evolutionary traits may provide important clues for the development of effective therapies to treat P. aeruginosa infections. In this study, 25 P. aeruginosa isolates were longitudinally sampled from the airways of four ventilator-associated pneumonia (VAP) patients. Pacbio and Illumina sequencing were used to analyse the in vivo evolutionary trajectories of these isolates. Our analysis showed that positive selection dominantly shaped P. aeruginosa genomes during VAP infections and led to three convergent evolution events, including loss-of-function mutations of lasR and mpl, and a pyoverdine-deficient phenotype. Specifically, lasR encodes one of the major transcriptional regulators in quorum sensing, whereas mpl encodes an enzyme responsible for recycling cell wall peptidoglycan. We also found that P. aeruginosa isolated at late stages of VAP infections produce less elastase and are less virulent in vivo than their earlier isolated counterparts, suggesting the short-term in vivo evolution of P. aeruginosa leads to attenuated virulence.

The host immune system offers a hostile environment with antimicrobials and reactive oxygen species (ROS) that are detrimental to bacterial pathogens, forcing them to adapt and evolve for survival. However, the contribution of oxidative stress to pathogen evolution remains elusive. Using an experimental evolution strategy, we show that exposure of the opportunistic pathogen Pseudomonas aeruginosa to sub-lethal hydrogen peroxide (H2O2) levels over 120 generations led to the emergence of pro-biofilm rough small colony variants (RSCVs), which could be abrogated by l-glutathione antioxidants. Comparative genomic analysis of the RSCVs revealed that mutations in the wspF gene, which encodes for a repressor of WspR diguanylate cyclase (DGC), were responsible for increased intracellular cyclic-di-GMP content and production of Psl exopolysaccharide. Psl provides the first line of defence against ROS and macrophages, ensuring the survival fitness of RSCVs over wild-type P. aeruginosa. Our study demonstrated that ROS is an essential driving force for the selection of pro-biofilm forming pathogenic variants. Understanding the fundamental mechanism of these genotypic and phenotypic adaptations will improve treatment strategies for combating chronic infections.

In this report, a Ti:Sapphire oscillator was utilized to realize synchronization-free stimulated emission depletion (STED) microscopy. With pump power of 4.6 W and sample irradiance of 310 mW, we achieved super-resolution as high as 71 nm. With synchronization-free STED, we imaged 200 nm nanospheres as well as all three cytoskeletal elements (microtubules, intermediate filaments, and actin filaments), clearly demonstrating the resolving power of synchronization-free STED over conventional diffraction limited imaging. It also allowed us to discover that, Dylight 650, exhibits improved performance over ATTO647N, a fluorophore frequently used in STED. Furthermore, we applied synchronization-free STED to image fluorescently-labeled intracellular viral RNA granules, which otherwise cannot be differentiated by confocal microscopy. Thanks to the widely available Ti:Sapphire oscillators in multiphoton imaging system, this work suggests easier access to setup super-resolution microscope via the synchronization-free STED.