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Early diagnosis of Epstein-Barr virus (EBV) can reduce the risk of major illnesses. Disadvantages of EBV antibody detection methods that are commonly used clinically include lengthy assay time, need for a lot of reagent, and low efficiency. Compared with traditional detection methods, microfluidics technology offers high throughput, low reagent consumption, less bio-contamination, and a higher degree of automation. Advantages of magnetic immunofluorescence technology include high detection efficiency and a strong signal. The combined advantages of the two methods can compensate for the shortcomings of traditional methods. In the present study, polymethyl methacrylate (PMMA) as the raw material was subjected to laser cutting and vacuum hot pressing to quickly obtain chips. Magnetic beads labeled with antigen and fluorescent microspheres labeled with anti-human antibody were then rapidly lyophilized into microspheres by freeze-drying and embedded into the chips. After incubation and cleaning, the last step was detection. Image J software was used to analyze the mean fluorescence intensity and obtain negative or positive test results. To determine the precision of the chip, high- and low-value samples of each item were retested 10 times. The mean values were calculated to obtain the relative standard deviation (RSD) for several common pathogens. Furthermore, the coincidence rate of clinical samples was tested using a chemiluminescence immunoassay (CLIA) to determine the potential clinical application value. The RSD of the precision test for each item was10%, indicating good precision. The precision of the accelerated stability test was not verified. Specificity test results revealed no cross-reaction with some common pathogen antibodies, indicating good specificity. It remains to be verified whether the antibodies detected by this method cross-react with other herpes simplex viruses, such as types 1 and 2, Kaposi's sarcoma-associated virus, and human herpes virus type 6 and 7. Of the 121 clinical samples tested, statistical analysis of the data indicated good agreement with the chemiluminescence immunoassay in clinical trials. EB viral capsid antigen (EB VCA) IgG positive coincidence rate was 95.77% (68/71), the negative coincidence rate was 86% (43/50) (Kappa=0.828

The aim of this study is to compare the trajectory of cross-kick technical movements of excellent taekwondo players in different weight classes and to investigate the relationship between weight class differences and the characteristics of cross-kick technical movements and the extent to which they affect the speed of movements. To this end, an artificial intelligence system is proposed for taekwondo field decision making, combining computer and applied mathematics knowledge. The angles, angular velocities, and moments of the joints of the lower limbs, as well as the movement time, displacement, and speed of the lower limbs, of the athletes in the three weight classes were significantly different ( P < 0.05 ).

Objectives The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally. The laboratory diagnosis of SARS-CoV-2 infection has relied on nucleic acid testing; however, it has some limitations, such as low throughput and high rates of false negatives. Tests of higher sensitivity are needed to effectively identify infected patients. Methods This study has developed fully automated chemiluminescent immunoassays to determine IgM and IgG antibodies to SARS-CoV-2 in human serum. The assay performance has been evaluated at 10 hospitals. Clinical specificity was evaluated by measuring 972 hospitalized patients and 586 donors of a normal population. Clinical sensitivity was assessed on 513 confirmed cases of SARS-CoV-2 by RT-PCR. Results The assays demonstrated satisfied assay precision with coefficient of variation of less than 4.45%. Inactivation of specimen did not affect assay measurement. SARS-CoV-2 IgM showed clinical specificity of 97.33 and 99.49% for hospitalized patients and the normal population respectively, and SARS-CoV-2 IgG showed clinical specificity of 97.43 and 99.15% respectively. SARS-CoV-2 IgM showed clinical sensitivity of 82.54, 92.93, and 84.62% before 7 days, 7–14 days, and after 14 days respectively, since onset of symptoms, and SARS-CoV-2 IgG showed clinical sensitivity of 80.95, 97.98, and 99.15% respectively at the same time points above. Conclusions We have developed fully automated immunoassays for detecting SARS-CoV-2 IgM and IgG antibodies in human serum. The assays demonstrated high clinical specificity and sensitivity, and add great value to nucleic acid testing in fighting against the global pandemic of the SARS-CoV-2 infection.

BACKGROUNDThe outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally. The laboratory diagnosis of SARS-CoV-2 infection has relied on nucleic acid tests. However, there are many limitations of nucleic acid tests, including low throughput and high rates of false negatives. More sensitive and accurate tests to effectively identify infected patients are needed.METHODSThis study has developed fully automated chemiluminescent immunoassays (CLIA) to determine IgM and IgG antibodies to SARS-CoV-2 in human serum. The assay performance has been evaluated at 10 hospitals. Clinical specificity was evaluated by measuring 972 hospitalized patients with diseases other than COVID-19, and 586 donors of a normal population. Clinical sensitivity was assessed on 503 confirmed cases of SARS-CoV-2 by RT-PCR and 52 suspected cases.RESULTSThe assays demonstrated satisfied assay precision with coefficient of variation (CV) of less than 4.45%. Inactivation of specimen does not affect assay measurement. SARS-CoV-2 IgM shows clinical specificity of 97.33% and 99.49% for hospitalized patients and normal population respectively. SARS-CoV-2 IgG shows clinical specificity of 97.43% and 99.15% for the hospitalized patients and the normal population respectively. SARS-CoV-2 IgM and IgG show clinical sensitivity of 85.88% and 96.62% respectively for confirmed SARS-Cov-2 infection with RT-PCR, of 73.08% and 86.54% respectively for suspected cases.CONCLUSIONSwe have developed fully automated immunoassays for detecting SARS-CoV-2 IgM and IgG antibodies in human serum. The assays demonstrated high clinical specificity and sensitivity, and add great value to nucleic acid testing in fighting against the global pandemic of the SARS-CoV-2 infection.

Native α1-antitrypsin (AAT) is a 52-kDa glycoprotein that acts as an antiprotease and is the physiological inhibitor of neutrophil serine proteases. The main function of AAT is to protect the lung from proteolytic damage induced by inflammation. AAT deficiency (AATD) is a codominant autosomal disorder caused by pathogenic mutations in SERPINA1 gene, leading to reduced levels of serum AAT. The deficiency is known to increase the risk of pulmonary emphysema and chronic obstructive pulmonary disease as a consequence of proteolytic imbalance induced by inflammation, associated in many instances with cigarette smoking and other environmental hazards. Currently, the available therapy for lung disease associated with AATD is serum purified human AAT injected into patients on a weekly basis. It would be advantageous to replace serum-derived AAT with a recombinant version which is stable and resistant to oxidation. We have expressed AAT in Escherichia coli as inclusion bodies and developed a highly efficient refolding and purification process. We engineered a series of mutant forms of AAT to achieve enhance thermostability and oxidation resistance. Moreover, we synthesized an active form of AAT via cysteine-pegylation to achieve a markedly extended half-life in vivo. The resulting molecule, which retains comparable activity to the wild-type form, is expected to be an improved therapeutic agent for treating hereditary emphysema. In addition, the molecule may also be used to treat other types of emphysema caused by smoking, cystic fibrosis, pulmonary hypertension, pulmonary fibrosis, and chronic obstructive pulmonary disease.

The speech recognition technology makes it possible for people to communicate with intelligent electronic devices. However, existing speech recognition algorithms are overly complex for small intelligent electronic devices (e.g., mini speakers, intelligent toys, intelligent remote controls, etc.). For this, an efficient speech recognition algorithm is proposed. Firstly, the Mel-scale Frequency Cepstral Coefficients (MFCC) is applied to extract features of voices. Secondly, the Support Vector Machines (SVM) is used to train speech classification models. Finally, a speech database is collected to validate the proposed algorithm. The speech database contains 500 audio files of 10 speech commands for an electric motor car driving assistant and 550 audio files of 11 speech commands for a intelligent remote control. The proposed method is evaluated via a 5-fold cross-validation, and experiments show that the propose method acquires 94.20% and 88.73% average accuracy rates for the electric motor car driving assistant and the intelligent remote control, respectively.

This study was performed to provide further evidence of inter-species competition between Gambusia affinis and Tanichthys albonubes . We assessed the growth performances of juvenile animals of the two species at different water velocities (0 and 1.5 body length per second [bl/s]) and ration levels (repletion- and medium-rations). For each treatment, 30 experimental fish were chosen randomly and cultured in a specially designed feeding equipment at 25 ± 1 °C. Initial body lengths and masses were measured in 50 fish randomly selected from the experimental animals. During the experiment, fish were fed twice (09:00 and 21:00) daily. After 30 days, food intake, mortality rates, body lengths, dry body masses, specific growth rates, and growth efficiencies were evaluated. The results showed that feeding rates of both G. affinis and T. albonubes had no significant differences between flowing (1.5 bl/s) and static (0 bl/s) waters, both in repletion and medium rations. Daily satiation of G. affinis and T. albonubes increased in a linear trend with feeding time. Feeding rates were significantly higher in G. affinis compared with T. albonubes ( P $_amp_$lt; 0.05). Mortality rates of G. affinis showed no significant difference between flowing and static waters at repletion ration while, under medium ration conditions, G. affinis died quite considerably in static water ( P $_amp_$lt; 0.05). Body lengths, dry masses, specific growth rates, growth efficiencies, and condition factors in G. affinis and T. albonubes showed no significant differences between flowing and static water conditions at repletion ration. However, at medium ration in flowing water, these parameters increased significantly in G. affinis ( P $_amp_$lt; 0.05), but reduced considerably in T. albonubes ( P $_amp_$lt; 0.05). These findings indicate that although T. albonubes had higher growth rates with adequate food supply, G. affinis had higher feeding rates and was more adaptable to water currents and lower ration levels. This shows that G. affinis may have more advantages in feed resource competition in the common distribution of natural stream habitats.

Somatic growth and reproduction were examined in individual laboratory-grown female Gambusia affinis fed with high (H), medium (M) and low (L) ration levels from birth to the first-time spawning. Results showed that the body length and weight, condition factor (CF), wet weight gain (WGw), specific growth rate in wet weight (SGRw) and ration levels in terms of energy (RLe) decreased significantly (p &lt, 0.05) with decreasing ration levels from birth to first-time spawning. On the contrary, the food conversion efficiency in terms of energy (FCEe) increased significantly (p &lt, 0.05) with the decreasing ration levels from birth to first-time sexual maturity. Furthermore, higher percentages of energy intake from food were allocated to somatic and gonad growth in M and L groups compared to the H group before sexual maturity, In addition, the time for first-time spawning in groups M and L was longer than that of the H group. As a result, the gonad-somatic index (GSI) and oocytes/embryos weight in M and L groups were similar to that of the H group, although the ovary weight and oocytes/embryos numbers were all lower than that of the H group. Also, similar growth performances were observed in second-generation offspring, which were produced by female parents fed with different ration levels. These findings suggest that the female G. affinis could produce a number of healthy offspring under conditions of food restriction, and that this could be achieved by increasing the energy allocated to gonad development, reducing fecundity and delaying spawning time. These life strategies ensured that G. affinis could survive and thrive in adverse environmental conditions and exhibit characteristics of invasive fish species.

To explore the differences in the swimming ability and environmental adaptive abilities between male and female Gambusia affinis, we assessed the differences in burst swimming speeds (Uburst), critical swimming speeds (Ucrit) and their related fin areas, and consumption of energy substances after starvation at 0 (control group), 15, 30, 45, and 60 days, respectively. The results showed that the pectoral and caudal fin areas did not differ significantly between male and female G. affinis. However, the dry mass, condition factors, and absolute contents of glycogen, lipids, and proteins were significantly elevated in females in the control group (P, Summary: The study explored the causes of variation in swimming performance with respect to morphological and physiological characteristics, which provides further information about environmental adaptive ability in Gambusia affinis.

Five isonitrogenous and isocaloric diets were fed to juvenile cobia, to assess the relative contribution of different proteins (fish meal, soybean meal, corn gluten and beer yeast) to the growth of cobia. The dietary effects on nitrogen and carbon turnover and on the isotopic diet-consumer discrimination factors (Δ15N and Δ13C) were also assessed. Growth results showed that the final body weight, growth rate, feed conversion ratio and protein efficiency ratio of cobia fed diets with alternative protein were significantly lower (P

Laboratory and field investigations were conducted to study the food habit of Chinese perch Siniperca chuatsi (Basilewsky) from first feeding through adult stage. Only fish larvae were consumed by Chinese perch larvae (2-21 days from hatching), and the presence of zooplankton did not have any significant effect on their survival rate. The ability of Chinese perch to feed on zooplankton is clearly limited by some innate factor. Instead of gill rakers, Chinese perch larvae have well-developed sharp teeth at the first feeding stage, and are well adapted to the piscivorous feeding habit unique to the larvae of Chinese perch, e.g. they bite and ingest the tails of other fish larvae. At the first feeding stage (2 days from hatching), daily rations were both very low, either in light or complete darkness. Although early-staged Chinese perch larvae (7-17 days from hatching) could feed in complete darkness, their daily rations were always significantly higher in light than in complete darkness. Late-staged Chinese perch larvae (21 days from hatching) were able to feed in complete darkness as well as in light, similar to the case of Chinese perch yearlings. Chinese perch yearlings (total length, 14-16 cm) consumed prey fish only and refused shrimp when visual cues were available (in light), but they consumed both prey when visual cues were not available (in complete darkness), suggesting that prey consumption by Chinese perch yearlings is affected by their sensory modality in predation. Both prey were found in the stomachs of similar-sized Chinese perch (total length, 14-32 cm) from their natural habitat, suggesting that shrimp are consumed by Chinese perch at night. Prey selection of Chinese perch with a length >38 cm, which consumed only fish in the field, appears to be based upon prey size instead of prey type. These results suggest that although environmental factors (e.g. light intensity) affect prey detection by Chinese perch, this fish is anatomically and behaviourally predisposed to prey on live fish from first feeding. This makes it a difficult fish to cultivate using conventional feeds.

Trash fish used as aquafeeds in marine cage cultivation sometimes induced environmental risk. In this study, nitrogen, phosphorus, and energy waste outputs were measured in four marine cage-cultured carnivorous fish species – Sciaenops ocellatus , Plectorhynchus cinctus , Epinephelus coioides , and Rhabdosargus sarba – fed with trash fish for 6 weeks in laboratory. Waste outputs of cultured fish were divided into soft tissues in uneaten feed, bones in uneaten feed, scales in uneaten feed, soluble uneaten feed, solid faeces, soluble faeces, urine, caducous scales, and other parts. The results showed that an increase in 1 g of fish mass produced: 1) 34.4–67.2 mg nitrogen in urine, uneaten feed, faeces, and caduceus scales; 2) 3.4–10.9 mg phosphorus in uneaten feed, faeces, and caduceus scales; and 3) 12.0–23.8 kJ in metabolism, uneaten feed, urine, and caduceus scales. In the nutrient budget, urine was the most important component of nitrogenous waste and accounted for 7.8–14.4% of total nitrogen input. Bones and scales in uneaten feed carried the bulk of phosphorus waste, and these accounted for 4.1–13.8% of total phosphorus input. Metabolism was the largest energy consumed and it accounted for 12.0–20.8% of total energy input. The ratio of energy:nitrogen:phosphorus in waste outputs was 1.0–1.4:3.9–4.5:1. The information on nutrient and energy in waste output of the four fish in this study would help to assess and predict pollution of trash fish used as aquafeeds.

The present study examines the effect of sustained exercise on glycolysis and fatty acids oxidation in the swimming muscles and liver in juvenile tinfoil barb (Barbonymus schwanenfeldii). The subjects were divided into one control group (water current speed of 0.0 bl s-1, body length per second) and two training groups (1.0 and 2.0 bl s−1), respectively. Results showed that the glycolysis was stimulated by high-speed training in the white muscle, accompanied by significantly increased activities of hexokinase, pyruvate kinase, and reduction in glycogen contents in training groups (P

The full-length cDNA of grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix) uncoupling protein 2 (UCP2) was obtained from liver. The grass carp UCP2 cDNA was determined to be 1152 bp in length with an open reading frame that encodes 310 amino acids. Five introns (Intron 3, 4, 5, 6 and 7) in the translated region, and partial sequence of Intron 2 in the untranslated region of grass carp UCP2 gene were also obtained. Gene structure comparison between grass carp and mammalian (human and mouse) UCP2 gene shows that, the UCP2 gene structure of grass carp is much similar to that of human and mouse. Partial UCP2 cDNA sequences of bighead carp (Aristichthys nobilis) and mud carp (Cirrhinus molitorella), were further determined. Together with the common carp (Cyprinus carpio) UCP2 sequence from GenBank (AJ243486), multiple alignment result shows that the nucleotide and amino acid sequences of the UCP2 gene, were highly conserved among the five major Chinese carps that belong to four subfamilies. Using beta-actin as control, the ratio UCP2/beta-actin mRNA (%) was determined to be 149.4 +/- 15.6 (common carp), 127.4 +/- 22.1(mud carp), 96.7 +/- 12.7 (silver carp), 94.1 +/- 26.8 (bighead carp) and 63.7 +/- 16.2 (grass carp). The relative liver UCP2 expression of the five major Chinese carps, shows a close relationship with their food habit: benthos and detritus-eating fish (common carp and mud carp) > planktivorious fish (silver carp and bighead carp) > herbivorous fish (grass carp). We suggest that liver UCP2 might be important for Chinese carps to detoxify cyanotoxins and bacteria in debris and plankton food.

Background Previous animal studies by us and others have indicated that catheter-administered plasmin or its des-kringle derivatives may be more appropriate alternatives to plasminogen activators for treating thrombolytic diseases, since it has a very short serum half-life and therefore does not result in hemorrhaging. We have previously produced recombinant miniPlasmin (mPlasmin) that was proven suitable for treating peripheral arterial occlusion in animal models. However, our previous results showed that non-specific cleavage at position K698 of mPlasmin during activation hindered the further development of this promising therapeutic candidate. In order to minimize or eliminate the non-specific cleavage problem, we performed saturation mutagenesis at the K698 position to develop a mutant form of mPlasmin for thrombolytic therapy. Methods We changed K698 to 16 other amino acids, with preferred E. coli codons. Each of these mutants were expressed in E. coli as inclusion bodies and then refolded, purified, and subsequently characterized by detailed kinetic assays/experiments/studies which identified highly active mutants devoid of non-specific cleavage. Results Activation studies indicated that at those conditions in which the wild type enzyme is cut at the non-specific position K698, the active mutants can be activated without being cleaved at this position. Conclusions From the above results, we selected two mutants, K698Q and K698N, as our lead candidates for further thrombolytic drug developments. The selected mutants are potentially better therapeutic candidates for thrombolytic therapy.