ObjectiveTo systematically investigate the identification characteristics of medicinal amber， elucidate its microscopic features， crystal structural properties， and elemental composition， and thereby provide a scientific foundation for quality control and authenticity verification. MethodsThirty-nine batches of amber samples were collected and analyzed through integrated techniques including morphological analysis， microscopic identification， powder X-ray diffraction （XRD）， Raman spectroscopy， Fourier-transform infrared （FTIR） spectroscopy， and inductively coupled plasma mass spectrometry （ICP-MS） to evaluate their morphological attributes， phase composition， molecular vibrational modes， and trace element profiles. Among them， the XRD experiment used Cu Kα radiation （λ=1.540 6 Å）， with a scanning angle range of 10° to 70° （2θ） and a step size of 0.02°， the Raman spectroscopy experiment employed a 785 nm laser， with a spectral measurement range of 3 400 to 50 cm^-1， a laser power of 300 mW， a laser intensity of 30%， and a scanning time of 100 to 1 000 ms， the infrared spectroscopy experiment used a carbon-sulfur lamp， with a scanning range of 4 000 to 500 cm^-1， a resolution of 4 cm^-1， and 3 scans， the ICP-MS experiment utilized frequency power of 1.2 kW， a double-pass cyclonic spray chamber， a sample introduction system flow rate of 0.7-1.0 L·min^-1， and an auxiliary gas flow of 0.2 L·min^-1. ResultsUnder orthogonal polarized light microscopy， medicinal amber exhibited an isotropic homogeneous structure， with partial samples containing inorganic impurities such as AsS and SiO₂. FTIR spectra revealed characteristic absorption peaks at 2 932-2 939 cm^-1 （C-H stretching vibrations）， 1 705-1 728 cm^-1 （C=O stretching vibrations）， and 880-887 cm^-1 （C=C deformation vibrations）， confirming the oxidative polymerization of terpenoid resin. Raman spectroscopy further identified distinctive peaks at 2 925 cm^-1， 2 870 cm^-1 （saturated C-H stretching）， and 1 648 cm^-1 （C=C stretching）， consistent with the structural features of oxidized-polymerized resin. ICP-MS analysis demonstrated that S， Al， Si， Fe， Na， and Ca were the predominant trace elements in medicinal amber. ConclusionThis study comprehensively evaluated medicinal amber's morphological attributes， phase composition， molecular vibrational modes， and trace elements through multimodal analytical techniques. The findings establish data support for establishing quality standards for medicinal amber and distinguishing it from synthetic resin imitations.

ObjectiveTo systematically investigate the identification characteristics of medicinal amber， elucidate its microscopic features， crystal structural properties， and elemental composition， and thereby provide a scientific foundation for quality control and authenticity verification. MethodsThirty-nine batches of amber samples were collected and analyzed through integrated techniques including morphological analysis， microscopic identification， powder X-ray diffraction （XRD）， Raman spectroscopy， Fourier-transform infrared （FTIR） spectroscopy， and inductively coupled plasma mass spectrometry （ICP-MS） to evaluate their morphological attributes， phase composition， molecular vibrational modes， and trace element profiles. Among them， the XRD experiment used Cu Kα radiation （λ=1.540 6 Å）， with a scanning angle range of 10° to 70° （2θ） and a step size of 0.02°， the Raman spectroscopy experiment employed a 785 nm laser， with a spectral measurement range of 3 400 to 50 cm^-1， a laser power of 300 mW， a laser intensity of 30%， and a scanning time of 100 to 1 000 ms， the infrared spectroscopy experiment used a carbon-sulfur lamp， with a scanning range of 4 000 to 500 cm^-1， a resolution of 4 cm^-1， and 3 scans， the ICP-MS experiment utilized frequency power of 1.2 kW， a double-pass cyclonic spray chamber， a sample introduction system flow rate of 0.7-1.0 L·min^-1， and an auxiliary gas flow of 0.2 L·min^-1. ResultsUnder orthogonal polarized light microscopy， medicinal amber exhibited an isotropic homogeneous structure， with partial samples containing inorganic impurities such as AsS and SiO₂. FTIR spectra revealed characteristic absorption peaks at 2 932-2 939 cm^-1 （C-H stretching vibrations）， 1 705-1 728 cm^-1 （C=O stretching vibrations）， and 880-887 cm^-1 （C=C deformation vibrations）， confirming the oxidative polymerization of terpenoid resin. Raman spectroscopy further identified distinctive peaks at 2 925 cm^-1， 2 870 cm^-1 （saturated C-H stretching）， and 1 648 cm^-1 （C=C stretching）， consistent with the structural features of oxidized-polymerized resin. ICP-MS analysis demonstrated that S， Al， Si， Fe， Na， and Ca were the predominant trace elements in medicinal amber. ConclusionThis study comprehensively evaluated medicinal amber's morphological attributes， phase composition， molecular vibrational modes， and trace elements through multimodal analytical techniques. The findings establish data support for establishing quality standards for medicinal amber and distinguishing it from synthetic resin imitations.

Objective To analyze the pathogenic composition of hand, foot and mouth disease (HFMD) cases and the antibody level of enterovirus 71 (EV-A71) in healthy people in Xi'an in 2022, so as to provide evidence for the prevention and control of HFMD. Methods Anal swabs or stool specimens of HFMD cases were collected. RT-PCR was used to detect enterovirus (EV) and serotype was identified. Enzyme-linked immunosorbent assay (ELISA) was used to detect EV-A71 IgG antibody levels in healthy people. Results A total of 172 positive cases were detected from 274 HFMD clinical specimens with a total detection rate of 62.77%, including 1 case of EV-A71 (0.58%), 95 cases of CV-A16 (55.23%), 64 cases of CV-A6 (37.21%), and 1 case of CV-A10(0.58%). CV-A16 was the dominant pathogen in spring and summer, and CV-A6 was the dominant pathogen in autumn and winter（χ²= 64.376，P＜0.001）. The age of HFMD cases caused by CV-A16 was older than the cases caused by CV-A6（t = 2.709，P = 0.007）. The positive rate of EV-A71 IgG antibodies in healthy people was 36.92% (168/455). The positive rate of EV-A71 IgG antibodies in men (32.35%) was lower than that in women (43.72%), and the difference was statistically significant (χ²= 6.605 , P = 0.014). The positive rate of EV-A71 IgG antibodies in people of all ages ranged from 21.95% to 54.78%, and the difference was statistically significant (χ²= 27.623 , P<0.001). Conclusion The main pathogens of hand, foot and mouth disease in Xi'an in 2022 are CV-A16 and CV-A6 . The positive rate of EV-A71 IgG antibodies in children under 5 years old is low , and EV-A71 vaccination should be strengthened.

Objective:To analyze the intraoperative hemodynamic management by hypotension prediction index(HPI)in one patient underwent robot-assisted laparoscopic cystectomy,and to provide the reference for anesthesia monitoring and hemodynamic management in the similar major surgery.Methods:The clinical data,intraoperative hemodynamic data,usage and dosage of vasoactive drugs,and clinical outcomes of one patient underwent robot-assisted laparoscopic cystectomy with HPI-guided intraoperative hemodynamic management were retrospectively analyzed,and the relevant literatures were reviewed.Results:The patient,a 72-year-old female,was admitted due to macroscopic hematuria for 5 months accompanied by dysuria for 3 months.The cystoscope results showed a 7 cm× 7 cm× 5 cm mass on the right side of the bladder trigone and a 4 cm × 3 cm × 3 cm mass near the bladder neck.The positron emission tomography/computed tomography(PET/CT)results showed thickening of the right posterior bladder wall with high metabolism,and the preliminary diagnosis was bladder malignancy.After preoperative anesthesia evaluation,the robot-assisted laparoscopic cystectomy was planned.After entering the operating room,the routine monitoring was conducted,and the monitor equipped with HPI software was used to guide intraoperative hemodynamic management.After routine anesthesia induction,the tracheal intubation was performed by video laryngoscope.The patient experienced intraoperative hypotension(IOH)for six times,the cumulative time of mean arterial pressure(MAP)＜65 mmHg was 13.7 min,accounting for 4.40％of the anesthesia duration,and the time-weighted average of MAP＜65 mmHg was 0.28 mmHg.The time range with HPI≥85 roughly overlapped with and included the period of MAP＜65 mmHg.At 146 time points with HPI≥85,the MAP remained greater than 65 mmHg at 68.5％(100/146)of the points.At 47 time points with MAP＜65 mmHg,HPI≥85 occurred at 97.9％(46/47)of the points.On the first postoperative day,the patient's hypersensitive cardiac troponin I was＜0.01 μg·L-1,and no perioperative adverse events occurred.The patient was discharged on the eighth day.Conclusion:HPI can promptly and accurately predict the occurrence of IOH in the patients undergoing robot-assisted laparoscopic cystectomy.The use of HPI-based hypotension correction strategies during surgery can maintain the time-weighted average of MAP＜65 mmHg at a lower level.

Objective:To explore the positive rates of 2019-nCoV nucleic acid at different time of courses of COVID-19.Methods:Patients with confirmed COVID-19 were enrolled in this study. Nasal and throat swabs were collected from different courses of disease. Real-time RT-PCR was used to detect 2019-nCoV nucleic acid.Results:From January 23 to February 20, 2020, a total of 120 confirmed cases of COVID-19 were reported in Xi’an, and 85 cases(70.83%) were positive in first detection. The COVID-19 cases included consistently nucleic acid positive and intermittently nucleic acid positive patients. 2019-nCoV nucleic acid could be detected in incubation period, and the longest observed duration of nucleic acid positive in this study was 26 days. The positive rate of 2019-nCoV nucleic acid was up to 84.21% on the 6th day, and the positive rate decreased as time passed during the course of COVID-19. Three patients (2.86%) were tested positive for 2019-nCoV nucleic acid again in nasal and throat swabs after discharge.Conclusions:The positive rate of 2019-nCoV nucleic acid was higher in the early stage of disease. 2019-nCoV nucleic acid can be detected in incubation period, and virus shedding may last for a long period.

Objective To understand the distribution of novel coronaviruses in the external environment of confirmed COVID-19 cases. Methods Environmental surface swab specimens such as bed rails, doorknob, closestool, hand washing sink, table, locker,ward pager, mobile phone, cup, clothes, were collected from the sentinel hospital of COVID-19, and samples were collected for the nucleic acid detection by RT-PCR. Results A total of 150 environmental samples were collected from 30 confirmed COVID-19 cases, 6 samples were determined to be novel coronaviruses postive (positive rate 4.00%). The total 14 mobile phone showed 3 novel coronaviruses positive.Among the 30 confirmed COVID-19 cases, 6 cases (positive rate 20.00%)were found novel coronaviruses in the external environment. Conclusions Novel coronaviruses exists in external environment of confirmed COVID-19 cases, which indicates the potential risk of COVID-19 infection.

Objective:To investigate the positive rates of 2019-nCoV nucleic acid in different specimens from confirmed COVID-19 cases during hospitalization and after discharge.Methods:Patients with confirmed COVID-19 were enrolled from designated hospitals. Nasal swabs, throat swabs, and specimens of stool, urine and blood were collected during hospitalization. After the patients were discharged, nasal swabs, throat swabs and stool specimens were collected during follow-up. Real-time RT-PCR was used to detect 2019-nCoV nucleic acid.Results:This study involved 25 confirmed COVID-19 cases. During hospitalization, all patients tested positive in both nasal and throat swab 2019-nCoV nucleic acid tests, and nine of them (36.00%) were positive in stool specimen test. Urine and blood specimen test results were all negative. Nasal swabs, throat swabs and stool specimens were collected from each patient 7 d and 14 d after discharge. Two patients (8.00%) tested positive for 2019-nCoV nucleic acid again in nasal and throat swab tests on 7 d, while all stool specimen tests were negative. No 2019-nCoV nucleic acid was detected in nasal swabs, throat swabs or stool samples on 14 d.Conclusions:2019-nCoV nucleic acid was detected in stool samples of confirmed COVID-19 cases during hospitalization. Nasal and throat swab nucleic acid tests turned positive again in some patients after discharge.

The recombinant plasmid carrying the gene encoding 3C protease of Enterovirus 71 (EV71) was constructed, the recombinant protein was then expressed and purified, the functional activity was also measured. Firstly, the 3C protease gene was inserted into pET28a vector, the constructed recombinant plasmid was transformed into E. coli BL21 (DE3) for expression under the induction of IPTG. The expressed protein was purified by affinity chromatography (Ni-NTA) and the N-terminus His-tag was cleaved by enterokinase from 3C protease. The activity of 3C protease was evaluated with fluorescent peptide substrates. It was verified by restriction analysis and sequencing that recombinant plasmid pET28a-3C was constructed correctly and functionally expressed in E. coli BL21 (DE3) resulting in the production of recombinant 3C protease with a size of 22kD. Both His-tag and non-His-tag (cleaved by enterokinase) 3C protease exhibited similar enzyme activity to 3B-3C fluorescent peptide with Km, Vmax and Kcat values of 22 microM, 434nM. Min(-1) and 0.0669 Min(-1), respectively. The optimial pH and temperature were 7.0 and 30-37 degrees C, respectively. The acquirement of recombinant purified 3C protease with high activity has paved the way of further studies on anti-viral inhibitors, structural protein assembly, vaccine development and detection methods of EV71.
Cloning, Molecular ; Cysteine Endopeptidases ; chemistry ; genetics ; metabolism ; Enterovirus A, Human ; enzymology ; genetics ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Kinetics ; Viral Proteins ; chemistry ; genetics ; metabolism