Distinct Assembly Processes Structure Planktonic Bacterial Communities Among Near- and Offshore Ecosystems in the Yangtze River Estuary.

The estuarine system functions as natural filters due to its ability to facilitate material transformation, planktonic bacteria play a crucial role in the cycling of complex nutrients and pollutants within estuaries, and understanding the community composition and assembly therein is crucial for comprehending bacterial ecology within estuaries. Despite extensive investigations into the composition and community assembly of two bacterial fractions (free-living, FLB; particle-attached, PAB), the process by which bacterioplankton communities in these two habitats assemble in the nearshore and offshore zones of estuarine ecosystems remains poorly understood. In this study, we conducted sampling in the Yangtze River Estuary (YRE) to investigate potential variations in the composition and community assembly of FLB and PAB in nearshore and offshore regions. We collected 90 samples of surface, middle, and bottom water from 16 sampling stations and performed 16S rRNA gene amplicon analysis along with environmental factor measurements. The results unveiled that the nearshore communities demonstrated significantly greater species richness and Chao1 indices compared to the offshore communities. In contrast, the nearshore communities had lower values of Shannon and Simpson indices. When compared to the FLB, the PAB exhibit a higher level of biodiversity and abundance. However, no distinct alpha and beta diversity differences were observed between the bottom, middle, and surface water layers. The community assembly analysis indicated that nearshore communities are predominantly shaped by deterministic processes, particularly due to heterogeneous selection of PAB; In contrast, offshore communities are governed more by stochastic processes, largely due to homogenizing dispersal of FLB. Consequently, the findings of this study demonstrate that nearshore and PAB communities exhibit higher levels of species diversity, while stochastic and deterministic processes exert distinct influences on communities among near- and offshore regions. This study further sheds new light on our understanding of the mechanisms governing bacterial communities in estuarine ecosystems.

Quantitative Predictive Studies of Multiple Biological Activities of TRPV1 Modulators.

TRPV1 channel agonists and antagonists, which have powerful analgesic effects without the addictive qualities associated with traditional analgesics, have become a focus area for the development of novel analgesics. In this study, quantitative structure-activity relationship (QSAR) models for three bioactive endpoints (Ki, IC50, and EC50) were successfully constructed using four machine learning algorithms: SVM, Bagging, GBDT, and XGBoost. These models were based on 2922 TRPV1 modulators and incorporated four types of molecular descriptors: Daylight, E-state, ECFP4, and MACCS. After the rigorous five-fold cross-validation and external test set validation, the optimal models for the three endpoints were obtained. For the Ki endpoint, the Bagging-ECFP4 model had a Q2 value of 0.778 and an R2 value of 0.780. For the IC50 endpoint, the XGBoost-ECFP4 model had a Q2 value of 0.806 and an R2 value of 0.784. For the EC50 endpoint, the SVM-Daylight model had a Q2 value of 0.784 and an R2 value of 0.809. These results demonstrate that the constructed models exhibit good predictive performance. In addition, based on the model feature importance analysis, the influence between substructure and biological activity was also explored, which can provide important theoretical guidance for the efficient virtual screening and structural optimization of novel TRPV1 analgesics. And subsequent studies on novel TRPV1 modulators will be based on the feature substructures of the three endpoints.

Real-time demonstration of a low-complexity PS scheme for 16QAM-DMT signals in an IM-DD system.

We experimentally demonstrated a low-complexity probabilistic shaping (PS) 16-ary quadrature amplitude modulation (16QAM) scheme based on intra-symbol bit-weighted distribution matching (Intra-SBWDM) for discrete multi-tone (DMT) symbols with field-programmable gate array implementation in an intensity modulation and direct detection (IM-DD) system. Different from the traditional PS scheme such as Gallager many-to-one mapping, hierarchical distribution matching and constant composition distribution matching, the Intra-SBWDM scheme with lower computation and hardware complexity does not need to continuously refine the interval to find the target symbol probability, nor does it need a look-up table, so it does not introduce a large number of extra redundant bits. In our experiment, four PS parameter values (k = 4, 5, 6, and 7) are investigated in a real-time short-reach IM-DD system. 31.87-Gbit/s net bit PS-16QAM-DMT (k = 4) signal transmission is achieved. The results show that the receiver sensitivity in terms of the received optical power of the real-time PS scheme based on Intra-SBWDM (k = 4) over OBTB/20 km standard single-mode fiber can be improved by about 1.8/2.2 dB at the bit error rate (BER) of 3.8 × 10-3, compared to the uniformly-distributed DMT. In addition, the BER is steadily lower than 3.8 × 10-3 during a one-hour measurement for PS-DMT transmission system.

Sparse I/Q-joint DNN nonlinear equalization based on progressive pruning for a photonics-aided 256-QAM MMW communication system.

An efficient nonlinear equalizer based on the pruning I/Q-joint deep neural network (DNN) is proposed and experimentally demonstrated to mitigate the nonlinearity in a photonics-assisted millimeter-wave (MMW) system with a high-order 256 quadrature-amplitude-modulation (QAM) format. Experimental findings reveal that implementing pruning on the I/Q-joint DNN can compress the computational overhead by 32% while accommodating 256-QAM E-band MMW transmission for a net throughput of 66.67 Gbps with 20.21% less complexity than the traditional Volterra nonlinear equalizer. Compared with the I/Q dual DNN with the same complexity, a 16% pruning ratio improvement is enabled by a robust pruning I/Q-joint DNN that further deciphers the I/Q relationship.

Beyond 300-Gbps/λ photonics-aided THz-over-fiber transmission employing MIMO single-carrier frequency-domain equalizer.

We experimentally realized a 320-GHz 320-Gbps/λ terahertz (THz) radio-over-fiber (RoF) system based on a photonics-aided scheme with the help of polarization-division multiplexing (PDM) technology and multiple-input, multiple-output (MIMO) transmission. In this system, the low-complexity MIMO single-carrier frequency-domain equalizer (SCFDE) is implemented to compensate for the polarization-related impairments of the PDM signal, and the demultiplexing performances between SCFDE and the commonly used constant modulus algorithm (CMA) are also compared in this proposed system. After 20-km standard single-mode fiber (SSMF) and 3-m 2 × 2 MIMO wireless link transmission, the bit error rate (BER) of the received 46-GBaud PDM 16-ary quadrature amplitude modulation (16QAM) signal satisfies the soft-decision forward error correction (SD-FEC) threshold with 15% overhead, which corresponds to a record-breaking net bit rate of 320 Gbit/s.

Real-time 100-GbE fiber-wireless seamless integration system using an electromagnetic dual-polarized single-input single-output wireless link at the W band.

This Letter demonstrates a real-time 100-GbE fiber-wireless seamless integration system operating at the whole W band (75-110 GHz). Based on a pair of commercial digital coherent optical modules, the real-time transparent transmission of 125-Gb/s dual-polarized quadrature phase-shift keying signal has been successfully achieved over two-spans of 20-km fiber and up to 150-m electromagnetic dual-polarized single-input single-output wireless link. To the best of our knowledge, this is the first real-time demonstration of 100-GbE signal transmission over >100-m wireless distance at the millimeter-wave band based on photonics. We believed this real-time and high-speed fiber-wireless seamless integration system with a wireless coverage up to hundreds of meters can significantly accelerate the progress of upcoming 6G.

SNR-enhanced signal delivery scheme with delta-sigma modulation in a four-mode fiber system.

This Letter proposes a scheme for optimizing the signal-to-noise ratio (SNR) of signal to improve the system performance by a 1 bit delta-sigma modulation (DSM) in a four-mode MDM system for mobile fronthaul. A 1 bit digitalized signal with an SNR of 60 dB from transmitter digital signal processing (Tx DSP) can be achieved. Based on this system, an experimental demonstration of the ultrahigh-order 1048576-QAM signal transmission over a 50 km strong-coupling few-mode fiber (FMF) is successfully realized. With DSP, the bit error rate (BER) of the received 1048576-QAM signals over four modes transmission is below the 20% soft-decision forward error correction (20% SD-FEC) threshold of 2.4 × 10-2. To the best of our knowledge, this is the first time that the combination of DSM technology and strong-coupling MDM system is achieved and that the highest-modulation order with DSM reported in MDM system is reached. This experimental demonstration of the proposed novel scheme in MDM system can provide an effective solution for ultra-large-capacity mobile fronthaul in the future.

Mechanical Properties of Low-Molecular-Weight Peptide Hydrogels Improved by Thiol-Ene Click Chemistry.

Low-molecular-weight peptide hydrogels can be formed by self-assembly through weak interactions, but the application of the hydrogel is influenced by its weak mechanical properties. Therefore, it is important to construct low-molecular-weight peptide hydrogels with excellent mechanical properties. In this work, we designed the pentapeptide molecule Fmoc-FFCKK-OH (abbreviated as FFCKK) with a sulfhydryl group, and another low-molecular-weight cross-linker N,N'-methylenebis(acrylamide) (MBA) was introduced to construct a hydrogel with excellent mechanical properties. The secondary structure change process of FFCKK and the assembly mechanism of hydrogel were analyzed using theoretical calculations and experimental characterizations. The occurrence of thiol-ene click chemistry provides covalent interaction in the hydrogel, and the synergistic effect ofcovalent interaction and hydrogen bonding improves the mechanical properties of the hydrogel by nearly 10-fold. The hydrogel was observed to be able to withstand a stress of 368 Pa and to break in a layer-by-layer manner by compression testing. The micromechanics of the hydrogels were characterized, and the excellent mechanical properties of the hydrogels were confirmed. The synergistic approach provides a new idea for the preparation of low-molecular-weight peptide hydrogels and facilitates the expansion of their potential applications in biomedical fields.

Controlling the Fluorescence Behavior of Hydrophobic Pigments by Supramolecular Self-Assembling on Organic Layered Silicate Minerals.

This research focused on the supramolecular self-assembly of organic fluorescent molecules on organically modified layered silicate minerals to design and prepare layered nanocomposites with excellent fluorescence properties. Aromatic hydrocarbons are hydrophobic and poorly loaded on the hydrophilic surface of layered silicate minerals, but they are easily captured by an organically modified mineral surface. Montmorillonite (MMT) and saponite (SAP), typical 2:1 type layered silicate minerals with different octahedral cations, were modified with the cationic surfactant octadecyl trimethylammonium chloride (OTAC) and loaded with pyrene (an aromatic hydrocarbon dye) with different molar ratios to the cationic surfactant by supramolecular self-assembling to construct fluorescent nanocomposites. The effect of pyrene concentration and the octahedral cation of the 2:1 type layered silicate minerals on photoluminescence properties was investigated. The fluorescence spectra of the nanocomposites prepared under low pyrene concentrations showed two bands at around 400 and 470 nm, corresponding to the monomer and excimer emissions; the band intensity of the excimer shoots up with the increase of pyrene concentration, reflecting different contributions from monomer and dimer species and the formation of radical aggregates. The excellent heat resistance of the layered silicate structure can effectively protect pyrene molecules from external environmental influences.

Decoupling the heterogeneity of sediment microbial communities along the urbanization gradients: A Bayesian-based approach.

Comprehending the response of microbial communities in rivers along urbanization gradients to hydrologic characteristics and pollution sources is critical for effective watershed management. However, the effects of complex factors on riverine microbial communities remain poorly understood. Thus, we established a bacteria-based index of biotic integrity (Ba-IBI) to evaluate the microbial community heterogeneity of rivers along an urbanization gradient. To examine the response of Ba-IBI to multiple stressors, we employed a Bayesian network based on structural equation modeling (SEM-BN) and revealed the key control factors influencing Ba-IBI at different levels of urbanization. Our findings highlight that waterborne nutrients have the most significant direct impact on Ba-IBI (r = -0.563), with a particular emphasis on ammonia nitrogen, which emerged as the primary driver of microbial community heterogeneity in the Liuyang River basin. In addition, our study confirmed the substantial adverse effects of urbanization on river ecology, as urban land use had the greatest indirect effect on Ba-IBI (r = -0.460). Specifically, the discharge load from wastewater treatment plants (WWTP) was found to significantly negatively affect the Ba-IBI of the entire watershed. In the low urbanized watersheds, rice cultivation (RC) and concentrated animal feeding operations (CAFO) are key control factors, and an increase in their emissions can lead to a sharp decrease in Ba-IBI. In moderately urbanized watersheds, the Ba-IBI tended to decrease as the level of RC emissions increased, while in those with moderate RC emissions, an increase in point source emissions mitigated the negative impact of RC on Ba-IBI. In highly urbanized watersheds, Ba-IBI was not sensitive to changes in stressors. Overall, our study presents a novel approach by integrating Ba-IBI with multi-scenario analysis tools to assess the effects of multiple stressors on microbial communities in river sediments, providing valuable insights for more refined environmental decision-making.

CovalentInDB: a comprehensive database facilitating the discovery of covalent inhibitors.

Inhibitors that form covalent bonds with their targets have traditionally been considered highly adventurous due to their potential off-target effects and toxicity concerns. However, with the clinical validation and approval of many covalent inhibitors during the past decade, design and discovery of novel covalent inhibitors have attracted increasing attention. A large amount of scattered experimental data for covalent inhibitors have been reported, but a resource by integrating the experimental information for covalent inhibitor discovery is still lacking. In this study, we presented Covalent Inhibitor Database (CovalentInDB), the largest online database that provides the structural information and experimental data for covalent inhibitors. CovalentInDB contains 4511 covalent inhibitors (including 68 approved drugs) with 57 different reactive warheads for 280 protein targets. The crystal structures of some of the proteins bound with a covalent inhibitor are provided to visualize the protein-ligand interactions around the binding site. Each covalent inhibitor is annotated with the structure, warhead, experimental bioactivity, physicochemical properties, etc. Moreover, CovalentInDB provides the covalent reaction mechanism and the corresponding experimental verification methods for each inhibitor towards its target. High-quality datasets are downloadable for users to evaluate and develop computational methods for covalent drug design. CovalentInDB is freely accessible at http://cadd.zju.edu.cn/cidb/.

First report of anthracnose caused by Colletotrichum kahawae on Hypericum chinensis in China.

Hypericum chinensis is growing in popularity amongst consumers in cut-flower and pop-flower market as an ornamental woody plant for its florid berry and colorful flower. In August 2019, a new leaf spot disease was observed on H. chinensis in three commercial nurseries in Kunming (25°05'N, 102°72'E), Yunnian province, China. Disease symptoms were observed on approximately 40% of the plants one year after planting and 30% of the leaves were infected. Leaf symptoms began as small, water-soaked lesions on young leaves which later became larger, dark brown and necrotic. The lesion size ranged from 0.2 to 2.8 cm in diameter. For pathogen isolation, three samples of symptomatic leaves were collected from four different nurseries. The leaves were cut into 0.5 mm pieces, surface sterilized using 70% ethanol for 30 s, and 3% NaOCl for 5 min, rinsed three times in sterilized distilled water and plated on potato dextrose agar (PDA) (Zhou et al. 2023). The plates were incubated at 26°C in the dark for 3 days. Eight isolates with comparable morphological characteristics were obtained. Initially, colonies produced pale gray to white aerial mycelia, turning dark gray after 5 days. The isolates produced hyaline, single celled, straight and cylindrical conidia, with mean size 9.7 to 14.8 µm long × 3.7 to 5.6 µm wide (n = 100). Morphological characteristics were consistent with Colletotrichum sp. (Bailey and Jeger 1992). For molecular analysis, genomic DNA was extracted from three representative isolates (XSD1, XSD3 and XSD5), amplified using the primers ITS1/ITS4 (Yin et al. 2012) and T1/Bt2b (Glass and Donaldson 1995) and submitted to sequencing (Weir et al. 2012). DNA sequences of the isolates XSD2, XSD3 and XSD8 were identical. DNA sequences of a representative isolate XSD2 were deposited in GenBank (accession no. MW202334 for ITS, and OR347007 for TUB 2). MegaBLAST analysis of the ITS and TUB2 sequences showed 99.5% and 99.3% similarity with C. kahawae strain ICMP 18539 (accession no. NR_120138.1 for ITS) and strain IMI319418 (JX145227.1 for TUB 2). Pathogenicity tests were conducted by inoculating the pathogen on healthy mature leaves of H. chinensis in the field. Ten leaves (two leaves/plant) were inoculated by spraying conidial suspension (106 spores/ml) of isolates XSD1, XSD3 and XSD5, and covered with plastic bags to maintain high humidity for 48 hours, respectively. Leaves treated with sterile distilled water served as a control. All inoculated leaves showed symptoms similar to those observed in the field at 23±5°C 10 days after inoculation. No symptoms developed on non-inoculated leaves. The pathogen was re-isolated from inoculated diseased leaves and identified as C. kahawae based on morphological and molecular characters. C. kahawae has been reported to cause leaf spot on cultivated rocket in Italy (Garibaldi et al. 2016), and anthracnose disease on tree tomato in Colombia (Rojas et al. 2018), to our knowledge, this is the first report of C. kahawae causing anthracnose on H. chinensis worldwide. Due to important ornamental and economic value of H. chinensis, the distribution of C. kahawae needs to be investigated and monitored for effective disease management strategies to be developed.

Intelligent Protein Design and Molecular Characterization Techniques: A Comprehensive Review.

In recent years, the widespread application of artificial intelligence algorithms in protein structure, function prediction, and de novo protein design has significantly accelerated the process of intelligent protein design and led to many noteworthy achievements. This advancement in protein intelligent design holds great potential to accelerate the development of new drugs, enhance the efficiency of biocatalysts, and even create entirely new biomaterials. Protein characterization is the key to the performance of intelligent protein design. However, there is no consensus on the most suitable characterization method for intelligent protein design tasks. This review describes the methods, characteristics, and representative applications of traditional descriptors, sequence-based and structure-based protein characterization. It discusses their advantages, disadvantages, and scope of application. It is hoped that this could help researchers to better understand the limitations and application scenarios of these methods, and provide valuable references for choosing appropriate protein characterization techniques for related research in the field, so as to better carry out protein research.

Gene expression analysis of resistant and susceptible rice cultivars to sheath blight after inoculation with Rhizoctonia solani.

BACKGROUND: Rice sheath blight, caused by Rhizoctonia solani Kühn (teleomorph: Thanatephorus cucumeris), is one of the most severe diseases in rice (Oryza sativa L.) worldwide. Studies on resistance genes and resistance mechanisms of rice sheath blight have mainly focused on indica rice. Rice sheath blight is a growing threat to rice production with the increasing planting area of japonica rice in Northeast China, and it is therefore essential to explore the mechanism of sheath blight resistance in this rice subspecies. RESULTS: In this study, RNA-seq technology was used to analyse the gene expression changes of leaf sheath at 12, 24, 36, 48, and 72 h after inoculation of the resistant cultivar 'Shennong 9819' and susceptible cultivar 'Koshihikari' with R. solani. In the early stage of R. solani infection of rice leaf sheaths, the number of differentially expressed genes (DEGs) in the inoculated leaf sheaths of resistant and susceptible cultivars showed different regularity. After inoculation, the number of DEGs in the resistant cultivar fluctuated, while the number of DEGs in the susceptible cultivar increased first and then decreased. In addition, the number of DEGs in the susceptible cultivar was always higher than that in the resistant cultivar. After inoculation with R. solani, the overall transcriptome changes corresponding to multiple biological processes, molecular functions, and cell components were observed in both resistant and susceptible cultivars. These included metabolic process, stimulus response, biological regulation, catalytic activity, binding and membrane, and they were differentially regulated. The phenylalanine metabolic pathway; tropane, piperidine, and pyridine alkaloid biosynthesis pathways; and plant hormone signal transduction were significantly enriched in the early stage of inoculation of the resistant cultivar Shennong 9819, but not in the susceptible cultivar Koshihikari. This indicates that the response of the resistant cultivar Shennong 9819 to pathogen stress was faster than that of the susceptible cultivar. The expression of plant defense response marker PR1b gene, transcription factor OsWRKY30 and OsPAL1 and OsPAL6 genes that induce plant resistance were upregulated in the resistant cultivar. These data suggest that in the early stage of rice infection by R. solani, there is a pathogen-induced defence system in resistant rice cultivars, involving the expression of PR genes, key transcription factors, PAL genes, and the enrichment of defence-related pathways. CONCLUSION: The transcriptome data revealed the molecular and biochemical differences between resistant and susceptible cultivars of rice after inoculation with R. solani, indicating that resistant cultivars have an immune response mechanism in the early stage of pathogen infection. Disease resistance is related to the overexpression of PR genes, key transcriptome factors, and PAL genes, which are potential targets for crop improvement.

Phylogenetic analysis and stress response of the plant U2 small nuclear ribonucleoprotein B″ gene family.

BACKGROUND: Alternative splicing (AS) is an important channel for gene expression regulation and protein diversification, in addition to a major reason for the considerable differences in the number of genes and proteins in eukaryotes. In plants, U2 small nuclear ribonucleoprotein B″ (U2B″), a component of splicing complex U2 snRNP, plays an important role in AS. Currently, few studies have investigated plant U2B″, and its mechanism remains unclear. RESULT: Phylogenetic analysis, including gene and protein structures, revealed that U2B″ is highly conserved in plants and typically contains two RNA recognition motifs. Subcellular localisation showed that OsU2B″ is located in the nucleus and cytoplasm, indicating that it has broad functions throughout the cell. Elemental analysis of the promoter region showed that it responded to numerous external stimuli, including hormones, stress, and light. Subsequent qPCR experiments examining response to stress (cold, salt, drought, and heavy metal cadmium) corroborated the findings. The prediction results of protein-protein interactions showed that its function is largely through a single pathway, mainly through interaction with snRNP proteins. CONCLUSION: U2B″ is highly conserved in the plant kingdom, functions in the nucleus and cytoplasm, and participates in a wide range of processes in plant growth and development.

Joint communication and radar sensing functions system based on photonics at the W-band.

The photonics-based technology has the advantages of wide bandwidth in millimeter wave (mm-wave) communication and radar sensing systems. In the present work, we propose a novel joint communication and radar sensing functions system based on photonics at the W-band. In the proposed system, the broadband linear frequency modulated (LFM) signal and high-speed M-quadrature amplitude modulation (MQAM) signal are simultaneously obtained by heterodyning two free-running external cavity lasers (ECLs). Based on this system, a communication rate of 78 Gbit/s and a radar with a 5-GHz bandwidth is achieved. This is a good solution to incorporate a high-speed communication and high-resolution radar sensing functions system.

W-band simultaneous vector signal generation and radar detection based on photonic frequency quadrupling.

In this paper, we propose and experiment with a dual-functional system that can simultaneously implement vector signal generation and radar detection based on frequency quadrupling. In the experimental demonstration, a generated W-band quadrature-phase-shift-keying (QPSK) vector signal is transmitted wirelessly over 1 m with a bit-error rate (BER) below 3.8 × 10-3. A radar working in the W band is investigated with a range resolution of 0.94 cm. To the best of our knowledge, this is the first time that simultaneous QPSK vector signal generation and radar detection in the W band has been realized.

THz-over-fiber transmission with a net rate of 5.12 Tbps in an 80 channel WDM system.

An experimental demonstration of the ultra-large-capacity terahertz (THz)-wave signal transmission over a 20-km wired and 54-m wireless distance in an 80-channel wavelength division multiplexing (WDM) system is successfully realized for the first time, to the best of our knowledge. Based on optical asymmetric single-sideband (ASSB) modulation and advanced digital signal processing (DSP) algorithms, we achieve a record line rate of 6.4 Tbit/s (net rate of 5.12 Tbit/s) in a THz-over-fiber communication system. This experimental demonstration can provide an effective solution for ultra-large-capacity THz-over-fiber communication in future 6G networks.

Wireless transmission of a 200-m PS-64QAM THz-wave signal using a likelihood-based selection radius-directed equalizer.

Based on a photonics-aided scheme, we achieve an experimental demonstration of a, to the best of our knowledge, record-breaking 200-m terahertz (THz)-wave wireless delivery at 335 GHz with the aid of a pair of high-gain polytetrafluoroethylene (PTFE) lenses. By using a 10-GBaud probabilistically shaped 64-ary quadrature amplitude modulation (PS-64QAM) signal and advanced digital signal processing (DSP) including a likelihood-based selection radius-directed equalizer (LBS-RDE), the single-carrier net bit rate of the wireless delivery reaches 44 Gbit/s. High-speed THz-wave communication with up to 200-m wireless distance is successfully realized based on a photonics-aided scheme for the first time.

Impact of carbapenem-resistant Acinetobacter baumannii infections on acute pancreatitis patients.

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) infections present great challenges in clinical practices with high mortality. The aim of this study is to identify the impact of CRAB infections on acute pancreatitis (AP). METHODS: A case-control study was performed via collecting data from March 1st, 2016 to August 1st, 2020 in two comprehensive teaching hospital. Clinical data of the CRAB-positive AP patients were analyzed and compared to a matched control group (case-control ratio of 1:1). Comparisons were preformed between with/without CRAB infections and multiple organ failure (MOF), respectively. Independent risk factors of overall mortality were determined via univariate and multivariate analyses. RESULTS: CRAB infections were associated with higher mortality (49.2% vs. 23.0%, P < 0.01). CRAB combined with MOF increased a mortality up to 90% (P < 0.01). MOF (Odds ratio (OR) = 21.49, 95% confidence interval (CI) = 5.26-87.80, P < 0.01), CRAB infections (OR = 3.58, 95%CI = 1.24-10.37, P = 0.02) and hemorrhage (OR = 3.70, 95%CI = 1.21-11.28, P = 0.02) were independent risk factors of overall mortality. Lung was the most common site of strains (37 of 82). CRAB strains were highly resistant (>60%) to ten of eleven common antibiotics, except for tigecycline (28%). CONCLUSION: High mortality rate in AP patients was associated with CRAB infections and further increased when CRAB infections combined with MOF.