The interaction between water-soluble CdS and gelatin 5n aqueous solution was explored using fluorescence,infrared (IR)and UV-Vis spectra at pH 12.0 and different temperatures.Results show that the formed complex had a strong ability to quench the fluorescence launched from gelatin.The fluorescence quenching data were analvzed according to Lineweave-Burk double-reciprocal equation and the gelatin had reacted with CdS to form a complex.This kind of static fluorescence quenching goes with non-radiation energy transfer happening within single molecule According to Lineweave-Burk equation,K(285 K:1.07×10~4 L/mol;292 K:9 69×10~3 L/mol;299 K:8.06×10~3 L/mol),the formation constants of the compound at different temperatures and the thermodynamic parameters(△H=-14.18 kJ/mol;△G=-21.98/-22.28/-22.36 kJ/mol;△S=27.36/27.74/27.36 J/K·mol) at certain temperatures were obtained,indicating that the binding force between them is mainly the static in nature.The binding locality was an area of 4.09 nm away from tryptophan residue in gelatin based on F(o)rster's non-radiation energy transfer mechanism.The results provide information for exploring the chemical mechanism of interaction between nanoparticle and this kind of biological macromolecule.

Objective To evaluate the effects of mechanical stretch preconditioning on pathological stretch-induced activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) signaling pathways in human type Ⅱ alveolar epithelial cells.Methods Human type Ⅱ alveolar epithelial cell line A549 cells cultured in vitro were randomly divided into 3 groups (n =24 each) using a random number table: control group (group Ⅰ), pathological stretch group (group Ⅱ), and mechanical stretch preconditioning group (group Ⅲ).In group Ⅰ , A549 cells were cultured routinely without receiving pathological stretch.In group Ⅱ , A549 cells were exposed to 20％ cyclic stretch at 0.3 Hz for 6 h.In group Ⅲ , A549 cells were exposed to 5％ cyclic stretch at 0.3 Hz for 60 min, and then exposed to 20％ cyclic stretch at 0.3 Hz for 6 h.After the end of the treatment, the cells were collected for determination of the cell viability (by methyl thiazolyl tetrazolium assay) and lactate dehydrogeuase (LDH)release (by colorimetric method).The concentrations of tumor necrosis factor-alpha (TNF-α),interleukin-8 (IL-8) and high mobility group box 1 (HMGB1) in the culture medium were detected using enzyme linked immunosorbent assay.The expression of total NF-κB, phosphorylated NF-κB, total STAT3 and phosphorylated STAT3 was detected using Western blot.The ratios of phosphorylated NF-κB to total NF-κB and phosphorylated STAT3 to total STAT3 were calculated to reflect the activation.Results Compared with group Ⅰ , the cell viability was significantly decreased, the amount of LDH released was increased, and the concentrations of TNF-α, IL-8 and HMGB1, and activation of NF-κB and STAT3 were increased in Ⅱ and Ⅲ groups.Compared with group Ⅱ , the cell viability was significantly increased, the amount of LDH released was decreased, and the concentrations of TNF-α, IL-8 and HMGB1, and activation of NF-κB and STAT3 were decreased in group Ⅲ.Conclusion The mechanism by which mechanical stretch preconditioning attenuates pathological stretch-induced damage to human type Ⅱ alveolar epithelial cells is related to inhibited activation of NF-κB and STAT3 signaling pathways.

Objective To evaluate the role of spinal RhoA/ROCK signaling pathway in the development of lipopolysaccharide (IP)-induced inflammatory pain(IP) in rats.Methods Fifty-two male Sprague-Dawley rats, weighing 180-220 g, were equally randomized into 4 groups using a random number table: normal saline group (group NS) , LPS group, RhoA inhibitor C3 exoenzyme group (group LC) , and ROCK inhibitor Y27632 group (group LY).Inflammatory pain was induced by injecting LPS 25 μl (300 ng) into the plantar surface of hindpaws in IP, LC and LY groups, while the equal volume of normal saline was injected instead in NS group.C3 exoenzyme 10 pg and Y27632 10 nmol were injected intrathecally at 30 min prior to LPS administration in LC and LY groups, respectively.Before LPS injection (T0) , and at 1, 3, 5, 12 and 24 h after LPS injection (T1-5) , the mechanical and thermal pain thresholds were measured.Five rats in each group were sacrificed after pain thresholds were measured at T3, and L4.5 segments of the spinal cord were removed for determination of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) mRNA expression in spinal dorsal horns by real-time reverse transcriptase-polymerase chain reaction.Results Compared with group NS, the mechanical and thermal pain thresholds were significantly decreased at T2-5in IP, LC and LY groups, and TNF-α and IL-1β mRNA expression was up-regulated at T3 in IP group.Compared with group IP, the mechanical and thermal pain thresholds were significantly increased at T2-5, and TNF-α and IL-1β mRNA expression was down-regulated at T3 in LC and LY groups.Conclusion Spinal RhoA/ROCK signaling pathway is involved in the development of LPS-induced IP in rats.

Objective To evaluate the relationship between the shedding of syndecan-4(SDC-4) in lung tissues and ventilator-induced lung injury in rats. Methods Thirty pathogen-free healthy adult male Wistar rats, weighing 220-250 g, were divided into 3 groups(n=10 each)using a random number table:control group(group C), mechanical ventilation with traditional tidal volume(VT)group(group T-VT) and mechanical ventilation with high VTgroup(group H-VT). The animals were anesthetized with pento-barbital sodium and tracheostomized. The rats kept spontaneous breathing in group C. The rats were me-chanically ventilated for 4 h with the VTset at 6 ml∕kg in group T-VT and with the VTset at 40 ml∕kg in group H-VT. Blood samples were collected immediately after the end of ventilation for measurement of serum SDC-4 concentrations by enzyme-linked immunosorbent assay. The left lung was lavaged, and broncho-alveolar lavage fluid was collected for determination of interleukin-1beta(IL-1β), IL-18, tumor necrosis factor-alpha and SDC-4 concentrations by enzyme-linked immunosorbent assay. The lungs were removed for determination of the wet to dry weight ratio and expression of SDC-4 protein and mRNA in lung tissues(by Western blot and real-time polymerase chain reaction, respectively)and for examination of the pathological changes. The lung injury scores were recorded. Results Compared with group C, the wet to dry weight ratio, lung injury scores, concentrations of IL-1β, IL-18, tumor necrosis factor-alpha and SDC-4 in bron-cho-alveolar lavage fluid and concentrations of SDC-4 in serum were significantly increased, the expression of SDC-4 mRNA was up-regulated, and the expression of SDC-4 was down-regulated in group H-VT(P<005), and no significant change was found in the parameters mentioned above in group T-VT(P>005).Marked pathological changes of lung tissues were found in group H-VT. Conclusion A large shedding of SDC-4 in lung tissues may be involved in the pathophysiological mechanism of ventilatior-induced lung injury in rats.

Objective To evaluate the efficacy of dexmedetomidine mixed with ropivacaine for thoracic paravertebral nerve blocks by multiple injections for preemptive analgesia on postoperative analgesia of patients undergoing thoracotomy. Methods Ninety patients, all genders, ASA Ⅰ or Ⅱ, aged 35-64, BMI 18-24 kg/m2, undergoing radical operation for esophageal carcinoma were randomly divided into three groups (each group 30 patients): group C received general anesthesia, group R received ropivacaine for thoracic paravertebral nerve block and group RD received dexmedetomidine mixed with ropivacaine for thoracic paravertebral nerve block.Three groups all used intravenous infusion of propofol, refentanyl and inhalation sevoflurane for anesthesia maintenance, and PCIA pump started before the end of surgery in 3 groups.Meanwhile, group R and group RD received ultrasound-guided T4-T8thoracic paravertebral nerve blocks by multiple injections on operation side preoperatively.In group R, the mixture of 0.5% ropivacaine 19 ml and 1ml of normal saline was injected, and in group RD, the mixture of dexmedetomidine 1 μg/kg and 19 ml of 0.5% ropivacaine was injected.The analgesia process lasted 48 h after surgery of these 3 groups, and the VAS score was maintained<4 points.When the VAS score was 4 or more points, intravenous injection of morphine 5- 10 mg was delivered. Postoperative PCIA liquid and morphine consumption, somnolence, nausea, vomiting, respiratory depression, itching and urinary retention was recorded. Additionally, the occurrences of adverse events about thoracic paravertebral nerve blocks were recorded.Results The dosages of propofol, refentanyl in group R and group RD were lower than those in group G:(7.2 ± 0.6),(6.1 ± 0.5)mg/(kg·h)vs.(8.1 ± 0.5)mg/(kg·h), and there were significant differences(P<0.05).The dosage of propofol in group RD was lower than that in group R: (6.1 ± 0.5) mg/(kg·h) vs. (7.2 ± 0.6) mg/(kg·h), and there was significant difference (P <0.05). Compared with group G, the consumption of PCIA liqud and the usage rate of morphine was reduced in group R and group RD (P < 0.05); the consumption of PCIA liqud and the usage rate of morphine was lower in group RD than that in group R(P<0.05).The rate of nausea and vomiting and itch in group R and group RD was lower than that in group G,and there were significant differences(P<0.05). No significant difference in somnolence showed between three groups (P > 0.05). Conclusions Ropivacaine combined with dexmedetomidine for target thoracic paravertebral nerve blocks by multiple injections for preemptive analgesia can significantly improve the efficacy of postoperative analgesia after thoracotomy, meanwhile,it can also save the dosage of anesthetic drugs during the operation.

Objective To evaluate the accuracy of respiratory variations of internal jugular vein (IJV) in monitoring fluid responsiveness in patients undergoing radical gastrectomy for gastric cancer.Methods Fifty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes,aged 40-64 yr,scheduled for elective radical gastrectomy for gastric cancer,were enrolled in this study.Before induction of anesthesia,the hemodynamic parameters such as heart rate,central venous pressure,cardiac index,stroke volume index (SVI),stroke volume variation and respiratory variation of IJV were recorded after haemodynamics was stable and were recorded again at 10 min after endotracheal intubation,and a loading dose of 6％ 130/0.4 hydroxyethyl starch 7 ml/kg was infused over 15 min.The parameters mentioned above were recorded within 5 min after loading dose.Patients were divided into 2 groups according to the percentage of increase in SVI (△SVI) after volume expansion:△SVI≥ 15％ was considered to be a positive response (responder group) and △SVI＜15％ was considered to be a negative response after volume expansion (non-responder group).Results The area under the receiver operating characteristic curve of respiratory variations of IJV in monitoring fluid responsiveness and 95％ confidence interval were 0.852 (0.744-0.961).Respiratory variation of IJV 24.6％ was considered as the cut-off value and used to monitor fluid responsiveness,and the sensitivity and specificity were 67.6％ and 92.3％,respectively.Conclusion Respiratory variation of IJV can be considered as an effective index in monitoring fluid responsiveness in the patients undergoing radical gastrectomy for gastric cancer.

Objective To evaluate the accuracy of respirophasic variation in carotid artery blood flow peak velocity(ΔVpeak-CA)in predicting fluid responsiveness in the patients undergoing surgery in the prone position. Methods Forty-three American Society of Anesthesiologists physical status Ⅰ-Ⅲ pa-tients of both sexes, aged 45-75 yr, with body mass index of 20-25 kg∕m2, scheduled for elective posteri-or approach lumbar surgery, were enrolled in the study.After induction of anesthesia, hydroxyethyl starch 130∕0.4 sodium chloride injection 7 ml∕kg was intravenously infused over 20 min when the patients were in the prone position.Subjects were classified as responders if stroke volume index increased≥15% after vol-ume expansion.The receiver operating characteristic curve for ΔVpeak-CA in determining positive fluid re-sponsiveness was drawn. Results The results of receiver operating characteristic curve analysis showed that: the cut-off value of ΔVpeak-CA in predicting positive fluid responsiveness was 7.94%, sensitivity 81.8%, specificity 70.0%, and the area under the curve(95% confidence interval)was 0.818 (0.378-0.757). Conclusion Respirophasic ΔVpeak-CA can accurately predict fluid responsiveness in the patients undergoing surgery in the prone position.

Objective To investigate the effect of different serum sodium levels on heart function and prognosis in very elderly patients with heart failure. Methods Totally 152 elderly patients(aged ≥ 85 years)with hyponatremia were enrolled.Based on the serum sodium level ,they were divided into mild(125 mmol/L ≤ Na+ < 135 mmol/L) ,moderate(125 mmol/L ≤ Na+ < 135 mmol/L) ,and severe hyponatremia(Na+ < 115 mmol/L)groups ,and 76 patients with normal blood sodium level(Na+ ≥ 135 mmol/L)were selected as control group. The general data ,levels of serum creatinine and N-terminal pro-brain natriuretic peptide (NTproBNP)and prognosis were compared among the above groups. Results Compared with the control group ,patients with severe hyponatremia were much older ,with more diuretics administration ,higher level of serum creatinine , lowerlevelofeGFRandleftventricularejectionfractions[(38.1±3.9)％ vs.(45.2±9.7)％ ].There were higher incidences of coronary atherosclerotic heart disease [72.4％ (n=21)vs. 56.6％ (n=43)] ,diabetes[41.4％ (n=12)vs. 23.7％ (n=18)] ,chronic renal insufficiency [22.6％ (n=8)vs. 11.8％ (n=9)] ,stroke[20.6％ (n=6)vs. 9.2％ (n=7)]in patients with severe hyponatremia compared with other groups. The severe hyponatremia group showed significantly higher levels of NTproBNP [(4823. 9 ± 588. 1 )ng/L v s. (1124. 4 ± 349. 1 )ng/L ,(1836. 2 ± 369. 3 )ng/L ,(2894. 1 ± 687. 3 )ng/L ]and higher rates of mortality [27.6％ (n=8) vs.5.3％ (n=4) ,7.6％ (n=6) ,13.6％ (n=6)]as compared to the control group ,mild and moderate hyponatremia groups. Furthermore ,length of stay in hospital were markedly longer in patients with severe hyponatremia than those with mild and moderate hyponatremia[(11.1 ± 7.1)d vs. (19.6 ± 5.7)d ,(16.1 ± 4.2)d] . Conclusions Hyponatremia is a common type of electrolyte disorder in very elderly patients with heart failure ,and severe hyponatremia may predictand increased risk of death.

OBJECTIVES: This study aimed to observe the clinical and immune response characteristics of vaccinated persons infected with the delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Yangzhou, China. METHODS: We extracted the medical data of 129 patients with delta-variant infection who were admitted to Northern Jiangsu People's Hospital (Yangzhou, China) between August and September, 2021. The patients were grouped according to the number of vaccine doses received into an unvaccinated group: a one-dose group and a two-dose group. The vaccine used was SARS-CoV-2-inactivated vaccine developed by Sinovac. We retrospectively analyzed the patients' epidemiological, clinical, laboratory, and imaging data. RESULTS: Almost all patients with delta-variant infection in Yangzhou were elderly, and patients with severe/critical illness were over 70 years of age. The rates of severe/critical illness (P=0.006), fever (P=0.025), and dyspnea (P=0.045) were lower in the two-dose group than in the unvaccinated group. Compared to the unvaccinated group, the two-dose group showed significantly higher lymphocyte counts and significantly lower levels of C-reactive protein (CRP), interleukin-6 (IL-6), and D-dimer during hospitalization and a significantly higher positive rate of immunoglobulin G (IgG) antibodies at admission (all P<0.05). The cumulative probabilities of hospital discharge and negative virus conversion were also higher in the two-dose group than in the unvaccinated group (P<0.05). CONCLUSIONS Two doses of the SARS-CoV-2-inactivated vaccine were highly effective at limiting symptomatic disease and reducing immune response, while a single dose did not seem to be effective.
Aged ; Aged, 80 and over ; Humans ; COVID-19/prevention & control* ; COVID-19 Vaccines/adverse effects* ; Critical Illness ; Immunity ; Retrospective Studies ; SARS-CoV-2 ; Vaccines, Inactivated/adverse effects* ; Viral Vaccines/adverse effects*