Objective To study risk factors associated with predisposition to Lm -ABM in adult patients and to evaluate the clinical features,management and out in this cohort of patients because Listeria monocytogenes (Lm) is the third most common cause of acute community acquired bacterial meningitis (Ac-ABM),after Streptococcus pneumoniae and Neisseria meningitides aetiologies.Methods A descriptive,prospective study carried out in a tertiary grade medical center emergency department in Beijing over a 10 -year period.During the study period,15 patients of Lm- ABM were included.Comparison of episodes of Lm - ABM versus other aetiologies was made.Results Fifteen episodes of Lm - ABM were identified in327 adult Ac - ABM patients.Three cohorts of individuals were vulnerable to Lm - ABM:the elderly ( RR=3.14; 95％ CI 1.84-5.35),the immunocompromised (RR =3.34; 95％ CI2.08-5.38),and pregnant women ( RR 12.48 ; 95％ CI 3.29 ～ 47.39 ).The classic triad of fever,neck stiffness,and altered mental status was present in 40％ (6 of 15) Lm - ABM patients.Similarly,40％ patients had at least one of cerebrospinal fluid (CSF) samples with features met the criteria of typical bacterial meningitis.The coverage of empirical antimicrobial therapy was microbiologically inadequate for 13 ( 86.7％ ) patients.The mortality rate was 33.3％ (5 of 15),and 7 (46.7％ ) of 15 patients led to an unfavorable outcome ( GOS ＜ 4),both of which were significantly higher than those in other aetiologies of Ac - ABM ( P =0.015P =0.009 respectively). Conclusions Our study showed the elderly,the immunocompromised patients,and pregnant women predisposed to Ac - ABM most likely to be Listeria monocytogenes aetiology.In contrast with similar previous reports, the current study showed that patients with meningitis due to Listeria monocytogenes did not present with atypical clinical features.A high proportion of patients received empirical antimicrobial therapy that did not cover Listeria monocytogenes.Lm - ABM is still a serious disease that leads to high morbidity and mortality rates.With these important caveats in mind,our findings have implications for clinical practice and food safety policy makers.

Objective:To investigate the application value of spectral computed tomo-graphy (CT) multi-parameter imaging in predicting gastric cancer lymph node metastasis.Methods:The retrospective case-control study was conducted. The clinicopathological data of 86 patients with gastric cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2014 to June 2017 were collected. There were 53 males and 33 females, aged from 22 to 87 years, with a median age of 53 years. All patients received abdominal plain scan and arterial and venous phase contrast spectral scan. Images of plain scan, 70 keV monochromatic and iodine-based images in arterial and venous phase were analyzed on post-processing working station. Observation indicators: (1) gastric cancer lymph node metastasis; (2) analysis of influencing factors for lymph node metastasis in gastric cancer; (3) introduction of special cases. Count data were described as absolute numbers. Univariate analysis was performed using the chi-square test or rank sum test. Multivariate analysis was conducted using the Logistic regression model.Results:(1) Gastric cancer lymph node metastasis: of the 86 patients, 64 cases had lymph nodes metastasis and 22 had no lymph nodes metastasis. (2) Analysis of influencing factors for lymph node metastasis in gastric cancer: results of univariate analysis showed that tumor growth pattern, tumor diameter, infiltration of peritumor fat, CT value in arterial phase, CT value in venous phase, iodine value in venous phase were related factors affecting lymph nodes metastasis in gastric cancer ( χ2=6.753, Z=-3.180, χ2=7.649, Z=-2.051, -2.971, -2.547, P<0.05). Results of multivariate analysis showed that infiltration of peritumor fat and the iodine value in venous phase were greater than 12(100 μg/cm 3) and not greater than 16(100 μg/cm 3), or greater than 16(100 μg/cm 3) were independent risk factors affecting lymph nodes metastasis in gastric cancer ( odds ratio=13.154, 3.761, 7.583, 95% confidence interval as 2.597-66.620, 1.893-8.572, 4.769-16.692, P<0.05). (3) Introduction of special cases: case 1 was male, aged 46 years. Results of preoperative spectral CT enhanced scan showed gastric antrum space occupying lesion combined with enlarged lymph nodes. During enhancement arterial phase, spectral CT 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall thickening with mild to moderate enhancement, clear fat space in serosa and enlarged lymph nodes in lesser curvature. The spectral CT 70 keV monochromatic images and corresponding iodine-based images below pylorus level in the transverse view showed subpyloric enlarged lymph nodes. During enhancement venous phase, the 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed layered enhancement of gastric antrum lesions and mucosal enhancement, with a high iodine value. The patient was diagnosed as gastric antrum cancer with lymph node metastasis, no serosal or peritumoral fat invasion. Results of postoperative pathological examination showed moderately differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Case 2 was male, aged 53 years. Results of preoperative spectral CT enhanced scan showed gastric cancer of lesser curvature combined with enlarged lymph nodes. During enhancement arterial phase, 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall heterogeneous thickening of lesser curvature, with moderate enhancement, obscure peritumor fat space, unclear serosa, and multiple enlarged lymph nodes in lesser curvature. During enhancement venous phase, 70 keV monochromatic images in the transverse view showed unclear boundary between lesions and enlarged lymph nodes in lesser curvature, obscure peritumor fat. During enhancement arterial phase, 70 keV monochromatic images of celiac trunk layer in the transverse view showed parasplenic artery lymph nodes, with circular enhancement and no enhancement in central necrotic elements. The patient was diagnosed as gastric cancer of lesser curvature with lymph node metastasis, serosal and peritumor fat invasion. Results of postoperative pathological examination showed poorly differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Conclusion:The infiltration of peritumor fat and iodine value in venous phase are independent factors affecting gastric cancer lymph node metastasis.

Objective To investigate the relationship between the expression of ITGAV and the radiosensitivity of NSCLC cells. Methods The expression of ITGAV in NSCLC and its relationship to the prognosis of patients who received radiotherapy were analyzed using bioinformatics methods. Differences in radiosensitivity between radio-resistant cells and parent cells were verified by clone formation experiment, and the protein expression of ITGAV was detected by Western blot. The transfection efficiency of si-ITGAV was determined by Western blot and qRT-PCR analyses. The best ITGAV interference sequence was selected to transfect A549R and H1299R cells. Clone formation experiment and flow cytometry were used to detect clone formation, apoptosis and cell cycle of A549R and H1299R cells. Results The expression of ITGAV in NSCLC tissues was significantly higher than that in normal tissues (P<0.05), and NSCLC patients with high ITGAV expression had poor prognosis. The clonogenic ability of the si-ITGAV group was significantly lower than that of the negative control group at 4, 6, 8Gy irradiation (all P<0.05). After 6 Gy irradiation, the apoptosis of the si-ITGAV group was increased (P_H1299R<0.0001, P_A549R=0.0002), the proportion of G₂/M phase cells to A549-siITGAV and H1299R-siITGAV cells was higher than that in the negative control group (P_H1299R<0.0001, P_A549R=0.0007). Conclusion Interfering with ITGAV expression can increase the radiosensitivity of NSCLC.

OBJECTIVETo investigate the application value of spectral CT in the differentiation of stage T3 and T4a gastric carcinoma.

METHODSData of 62 gastric cancer patients of stage T3 and T4a undergoing abdominal spectral CT examination in the First Affiliated Hospital of Zhengzhou University from December 2013 to December 2014 were collected retrospectively. There were 38 male and 24 female patients, with age of 33 to 77(58.6±10.4) years old. Abdominal double-phase enhanced scanning in gemstone spectral imaging mode was used to measure Iodine concentration (IC, 100 μg/ml) and water concentration(WC, 100 μg/ml) of perigastric fat tissue adjacent to the lesion during arterial phase(AP) and venous phase(VP), and normalized iodine concentration (nIC) was calculated respectively(nIC=IC/IC of aorta on the same slice). IC, WC, nIC of arterial phase and venous phase between stage T3 and T4a lesions were compared with double independent sample t test and compared with pathology. The diagnostic efficacy was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTSDuring arterial phase in stage T4a cases, IC (100 μg/ml) was -5.19±0.81 and nIC was -0.05±0.01, which was significantly higher than -3.44±1.54 (P=0.000) and -0.03±0.01 (P=0.000) in stage T3 cases. During venous phase in T4a cases, IC (100 μg/ml) was -3.78±0.94 and nIC was -0.04±0.01, which was significantly higher than -1.62±1.43 (P=0.000) and -0.02±0.02 (P=0.000) in stage T3 cases. As compared to arterial phase, IC and nIC of stage T4a and T3 of venous phase were more significantly different (all P<0.05). WC of stage T4a during arterial and venous phase was 955.72±15.68 and 949.86±17.36 respectively, while WC of stage T3 during arterial and venous phase was 947.77±18.43 and 942.46±18.53 respectively. There were no significant differences in WC between two stage cases during arterial and venous phase (P=0.106, P=0.143). ROC analysis showed that area under the ROC of IC and nIC during arterial phase was 0.829 and 0.867 respectively, and cut-off value of nIC was -0.039 for differentiation of stage T3 and T4a with corresponding 83.3% of sensitivity and 75.0% of specificity; area under the ROC of IC and nIC during venous phase was 0.873 and 0.905 respectively, and cut-off value of nIC was -0.031 for differentiation of stage T3 and T4a with corresponding 81.0% of sensitivity and 85.0% of specificity.

CONCLUSIONSAbdominal spectral CT scan is useful in the differentiation of stage T3 and T4a gastric carcinoma. The IC of perigastric fat tissue is significantly higher in stage T4a gastric carcinoma compared to stage T3 gastric carcinoma. Higher diagnostic efficacy can be obtained when taking -0.031 as the cut-off value of nIC during venous phase.

Adipose Tissue ; Adult ; Aged ; Female ; Humans ; Iodine ; Male ; Middle Aged ; Neoplasm Staging ; ROC Curve ; Retrospective Studies ; Sensitivity and Specificity ; Stomach Neoplasms ; diagnosis ; Tomography, X-Ray Computed

OBJECTIVETo investigate the preoperative assessment value of spectral CT quantitative parameters in lymph node metastasis of gastric cancer.

METHODSFrom December 2013 to June 2015, clinical and image data of 86 patients with gastric cancer confirmed by gastroscope pathology undergoing preoperative enhanced CT were prospectively collected. Enhanced CT included nonenhanced CT of conventional 120 kVp mode, arterial phase (AP) and venous phase (VP) with GSI mode on Discover GSI CT scanner. The raw data were transferred to ADW4.6 workstation to reconstruct the monochromatic images at 70 keV and iodine-based images in AP and VP with 1.25 mm thickness. The short diameter, long diameter, ratio of short to long diameter, CT attenuation and iodine value of lymph nodes in each phase were measured and recorded. Pathology results were used as golden standard. The spectral CT quantitative parameters of positive and negative lymph nodes were compared by t test and the sensitivity and specificity analyses were performed by ROC curves. This clinical study registration number 81271573.

RESULTSAmong these 86 gastric cancer patients (53 male and 33 female), tumors of 28 cases were in upper part, of 12 cases in middle part, of 27 cases in distal part and of 19 cases involved two parts. Thirty-five cases were differentiated type and 51 cases were undifferentiated type. A total of 1 072 lymph nodes were found in operation, of which 412 nodes were positive and 660 were negative. Among 552 lymph nodes found in CT images, 338 nodes were positive and 214 were negative. Compared to negative lymph nodes, short diameter [(9.52±3.58) mm vs. (6.48±2.94) mm, t=4.639, P=0.000], ratio of short to long diameter (0.82±0.14 vs. 0.61±0.08, t=13.514, P=0.000), CT attenuation in precontrast [(20.44±6.77) Hu vs. (16.06±7.14) Hu, t=3.154, P=0.002], CT attenuation in AP[(61.71±11.78) Hu vs. (40.11±10.18) Hu, t=9.588, P=0.000], CT attenuation in VP[(71.34±13.03) Hu vs. (53.81±11.39) Hu, t=7.888, P=0.000], iodine value in AP [(16.17±4.22) 100 μg/cmvs. (8.03±3.10) 100 μg/cm, t=9.781, P=0.000], the iodine value in VP [(20.13±6.04) 100 μg/cmvs. (11.58±4.13) 100 μg/cm, t=10.147, P=0.000] of positive lymph nodes were greater. The long diameter was not significantly different between positive and negative lymph nodes [(11.71±5.63) mm vs. (10.64±3.20) mm, t=1.380, P=0.169]. The area under ROC curve of short diameter, ratio of short to long diameter, CT attenuation in precontrast, AP and VP, iodine value in AP and VP of lymph nodes was 0.600, 0.880, 0.648, 0.832, 0.755, 0.864, 0.835, respectively. Taking the ratio of short to long diameter over 0.72 as diagnosis standard, the sensitivity was 75.6% and the specificity was 93.5%. Taking the CT number in AP over 49.75 Hu, the sensitivity was 66.9% and the specificity was 88.8%. Taking the CT number in VP over 59.80 Hu, the sensitivity was 69.9% and the specificity was 77.6%. Taking the iodine value in AP over 9.65 (100 μg/cm), the sensitivity was 80.4% and the specificity was 82.2%. Taking the iodine value in VP over 15.65 (100 μg/cm), the sensitivity was 69.9% and the specificity was 86.9%. Combinong the ratio of short to long diameter with the iodine value in AP, the sensitivity was 95.2% and the specificity was 76.9%.

CONCLUSIONSThe ratio of short to long diameter, the iodine value and CT attenuation in AP and VP of lymph nodes in spectral CT are important criteria to evaluate the metastasis of gastric cancer. Combining the ratio of short to long diameter with the iodine value in AP can obviously improve the sensitivity.

Female ; Gastroscopy ; Humans ; Iodine Radioisotopes ; Lymph Nodes ; diagnostic imaging ; pathology ; Lymphatic Metastasis ; diagnostic imaging ; Male ; ROC Curve ; Sensitivity and Specificity ; Stomach Neoplasms ; diagnostic imaging ; Tomography, X-Ray Computed ; instrumentation ; methods

Objective To evaluate the influence of preset adaptive statistical iterative reconstruction-V (ASIR-V) techniques on image quality and radiation dose reduction of abdominal CT in phantom,and to investigate the optimal ASIR-V level.Methods Abdominal anthropomorphic phantom was scanned using Revolution CT,when noise index (NI) were set as 6,8,10,12 and 14,respectively.Then 0-100％ ASIR-V and conventional scan was performed and 55 sets of images were obtained.CT value,noise,subjective score and radiation dose were recorded,and the optimal ASIR-V was obtained.Subjective scores of images in each group were compared using rank sum test,and CT value,noise and radiation dose were compared with one way ANOVA and paired t test.Results The image subjective score unchanged when NI was 6,8 or 10,slightly increased when NI was 12 and 14 with 0-40％ ASIR-V,and decreased above 50％ ASIR-V at all NI.When NI was 6,8 or 10,more than 70％ ASIR-V image subjective score fell below 3 points.When NI was 12 or 14 group,more than 60％ ASIR V subjective score fell below 3 points.The image quality score of conventional scan had no difference with 40％ ASIR-V when NI was 6,8 or 10,respectively (P=0.626,0.915,0.514),and inferior to 40％ ASIR-V when NI was 12 or 14 (P=0.041,0.036),while in all NI group,image quality score of conventional scan was superior to 60％ ASIR-V (P=0.021,0.012,0.015,0.014,0.007).CT values and image noises had no significant differences in different parts in all NI groups (all P＞0.05).CT dose index volume (CTDIvol) continuing decreased with ASIR-V.Compared with that of conventional scan,at 40％,50％ and 60％ ASIR-V,CTDIvol reduced by 49.82％,62.51％ and 71.63％,respectively.Conclusion Preset ASIR-V can reduce radiation dose obviously while maintaining the overall image quality,and 40％-60％ ASIR-V can be recommended for abdominal CT in clinical application.

Objective:To investigate the predictive model construction of anastomotic thickening character after radical surgery of esophageal cancer based on computed tomogralphy(CT) radiomics and its application value.Methods:The retrospective cohort study was conducted. The clinicopathological data of 202 patients with esophageal squamous cell carcinoma (ESCC) who were admitted to The First Affiliated Hospital of Zhengzhou University from January 2013 to June 2021 were collected. There were 147 males and 55 females, aged (63±8) years. Based on random number table, 202 patients were assigned into training dataset and validation dataset at a ratio of 7:3, including 141 cases and 61 cases respectively. Patients underwent radical resection of ESCC and enhanced CT examination. Observation indicators: (1) influencing factor analysis of malignant anas-tomotic thickening; (2) construction and evaluation of predictive model; (3) performance comparison of 3 predictive models. The normality of continuous variables was tested by Kolmogorov-Smirnov method. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was analyzed using the Mann-Whintney U test. Count data were represented as absolute numbers, and comparison between groups was analyzed using the chi-square test or Fisher's exact probability. The consistency between subjective CT features by two doctors and measured CT numeric variables was analyzed by Kappa test and intraclass correlation coefficient (ICC), with Kappa >0.6 and ICC >0.6 as good consistency. Univariate analysis was conducted by corresponding statistic methods. Multivariate analysis was conducted by Logistics stepwise regression model. The receiver operating characteristic (ROC) curve was drawn, and area under curve (AUC), Delong test, decision curve were used to evaluate the diagnostic efficiency and clinical applicability of model. Results:(1) Influencing factor analysis of malignant anastomotic thickening. Of the 202 ESCC patients, 97 cases had malignant anastomotic thickening and 105 cases had inflammatory anastomotic thickening. The consistency between subjective CT features by two doctors and measured CT numeric variables showed Kappa and ICC values >0.6. Results of multivariate analysis showed that the maximum thickness of anastomosis and CT enhancement pattern were independent influencing factors for malignant anastomotic thickening[ hazard ratio=1.46, 3.09, 95% confidence interval ( CI) as 1.26-1.71,1.18-8.12, P<0.05]. (2) Construction and evaluation of predictive model. ① Clinical predictive model. The maximum thickness of anasto-mosis and CT enhancement pattern were used to construct a clinical predictive model. ROC curve of the clinical predictive model showed an AUC, accuracy, sensitivity, specificity as 0.86 (95% CI as 0.80-0.92),0.77, 0.77, 0.80 for the training dataset, and 0.78 (95% CI as 0.65-0.89), 0.77, 0.77, 0.80 for the validation dataset, respectively. Results of Delong test showed no significant difference in AUC between the training dataset and validation dataset ( Z=1.22, P>0.05). ② Radiomics predictive model. A total of 854 radiomics features were extracted and 2 radiomics features (wavelet-LL_first order_ Maximum and original_shape_VoxelVolume) were finally screened out to construct a radiomics predictive model. ROC curve of the radiomics predictive model showed an AUC, accuracy, sensitivity, specificity as 0.87 (95% CI as 0.81-0.93), 0.80, 0.75, 0.86 for the training dataset, and 0.73 (95% CI as 0.63-0.83), 0.80, 0.76, 0.94 for the validation dataset, respectively. Results of Delong test showed no significant difference in AUC between the training dataset and validation dataset ( Z=-0.25, P>0.05). ③ Combined predictive model. Results of multivariate analysis and radiomics features were used to construct a combined predictive model. ROC curve of the combined predictive model showed an AUC, accuracy, sensitivity, specificity as 0.93 (95% CI as 0.89-0.97),0.84, 0.90, 0.84 for the training dataset, and 0.79 (95% CI as 0.70-0.88), 0.89, 0.86, 0.91 for the validation dataset, respectively. Results of Delong test showed no significant difference in AUC between the training dataset and validation dataset ( Z=0.22, P>0.05). (3) Performance comparison of 3 predictive models. Results of Hosmer-Lemeshow goodness-of-fit test showed that the clinical predictive model, radiomics predictive model and combined predictive model had a good fitting degree ( χ2=4.88, 7.95, 4.85, P>0.05). Delong test showed a significant difference in AUC between the combined predictive model and clinical predictive model, also between the combined predictive model and radiomics predictive model ( Z=2.88, 2.51, P<0.05 ). There was no significant difference in AUC between the clinical predictive model and radiomics predictive model ( Z=-0.32, P>0.05). The calibration curve showed a good predictive performance in the combined predictive model. The decision curve showed a higher distinguishing performance for anastomotic thickening character in the combined predictive model than in the clinical predictive model or radiomics predictive model. Conclusions:The maximum thickness of anastomosis and CT enhancement pattern are independent influencing factors for malignant anastomotic thickening. Radiomics predictive model can distinguish the benign from malignant thickening of anastomosis. Combined predictive model has the best diagnostic efficacy.

Objective:To explore the optimum time of ambulation of atrial fibrillation patients after radiofrequency ablation, to provide basis for patients' early postoperative rehabilitation.Methods:By convenient sampling method, a total of 120 patients with atrial fibrillation after radiofrequency ablation were collected at Yanghu Branch and City Branch of Changzhou Second People's Hospital from January 2020 to May 2021. They were divided into the early group, middle group and late group according to the random number table method, each group were 40 cases. All patients received routine postoperative intervention, the time of ambulation were 4, 6 and 12 h after operation in the early group, middle group and late group, respectively. The complication rate within 24 h after operation was compared among the three groups, and the comfort level of the three groups at 24, 48 and 72 h after operation was evaluated with Comfort Status Scale (GCQ).Results:Finally, 111 patients were included, including 37 in the early group, 38 in the middle group and 36 in the late group. There was no significant difference in the incidence of bleeding or hematoma, urinary retention, lumbago within 24 h after operation among the three groups ( P>0.05). The incidence of postural hypotension within 24 h after operation in the early group was 2.7% (1/37), which was lower than 21.1% (7/38) and 25.0% (9/36) in the middle and late groups, with a statistically significant difference ( χ2=4.86, 7.67, both P<0.05). At 48 and 72 h after operation, the scores of physiological dimension, psychological dimension and the total score of GCQ in the early group were (20.68 ± 3.07), (22.54 ± 3.35), (81.68 ± 6.11) and (22.54 ± 3.73), (24.38 ± 2.49), (84.92 ± 6.37), higher than those in the middle group (19.16 ± 2.19), (21.32 ± 2.27), (78.24 ± 5.58), (20.93 ± 2.85), (22.32 ± 2.04), (81.66 ± 6.56), and those in the late group (18.44 ± 1.50) (21.31 ± 1.99), (78.06 ± 4.32), (20.89 ± 2.25), (21.58 ± 1.86), (80.28 ± 6.44), the differences were statistically significant ( t values were 2.19-4.15, all P<0.05). Conclusions:Ambulation at 4 h after operation does not increase peripheral vascular complications, but can reduce the incidence of postural hypotension and improve the comfort of patients with atrial fibrillation after radiofrequency ablation.

Objective:To explore the change of medical students' self-regulated learning from traditional medicine to clinical practice in emergency department, and to provide direction for optimizing the curriculum system and exploring new education and teaching methods.Methods:Through questionnaires and in-depth interviews, the self-regulated learning scale was applied, and the 6-level Likert scale was used for scoring. A total of 118 medical students, including 8-year undergraduates majoring in clinical medicine of Peking Union Medical College, were evaluated in the traditional medicine course stage (traditional group), emergency clinical practice stage (clinical group), and emergency clinical practice stage of the "4 + 4" reform pilot class ("4 + 4" pilot class group) of clinical medicine. The learning situation and related influencing factors were self-regulated. SPSS 23.0 was used for one-way analysis of variance.Results:Among the eight-year medical students of Peking Union Medical College, there were 48 males (40.7%) and 70 females (59.3%). The three groups of 8-year traditional medicine course stage, 8-year emergency clinical practice stage and "4 + 4" pilot class of emergency clinical practice stage were analyzed. The results showed that the total score of self-regulated learning ability in the clinical group was significantly lower than that in the traditional group [(326.2±31.9) vs. (347.7±40.2) points]. The subscales of self-regulated learning ability were analyzed respectively. In the learning motivation subscale, the score of external goal orientation of the clinical group is significantly lower than that of the traditional group [(8.9±2.3) vs. (10.0±2.9) points] and the score of the "4 + 4" pilot class group is significantly higher than that of the clinical group [(11.0±3.5) vs. (8.9±2.3) points]. In the learning strategy subscale, there was no significant difference among the three groups. In the resource management subscale, the scores of time and study environment [(6.5±1.1) vs. (7.5±1.9) points], learning management [(37.7±4.0) vs. (40.3±3.0) points] and help-seeking [(32.7±5.3) vs. (37.5±9.5) points] of the clinical group decreased significantly compared with those of the traditional group, while the scores of learning management [(40.2±7.3) vs. (37.7±4.0) points] and help-seeking [(38.7±7.6) vs. (32.7±5.3) points] of the "4+4" pilot class group increased significantly compared with those of the clinical group.Conclusion:The self-regulated learning of clinical medical students has changed significantly during the transition from traditional medical class to emergency clinical practice. The decrease of external goal orientation and resource management may be the important reason for the decline of the self-regulated learning ability of 8-year undergraduate medical students in the clinical environment during emergency practice.

OBJECTIVE To optimize the water extraction process of Maxing kechuan granules. METHODS With the contents of ephedrine hydrochloride， bergenin， prim-O-glucosylcimifugin， 5-O-methylvisamin， naringin and hesperidin and the rate of extraction as the evaluation indexes， the weight was determined by the analytic hierarchy process（APH）-entropy weight method， and the comprehensive score was calculated as the response value. Based on the single-factor test， the Box-Behnken response surface method was used to investigate the factors， and the best water extraction process of Maxing kechuan granules was optimized； process validation was also carried out. RESULTS The best water extraction process of Maxing kechuan granules optimized was as follows： soaking for 40 minutes， adding 8 times water， and extracting for 180 minutes. After three validation tests， the comprehensive score was 94.82 （RSD＝0.96%， n＝3）， which had a small difference from the predicted value of 94.64. CONCLUSIONS The water extraction process of Maxing kechuan granules is stable and reliable， which can provide a reference for the development of the preparation.