The chronic-hypoxia-resistant gastric cancer cell line was established, and its biological characteristics were explored and compared with the parental cell line. Gastric cancer cell lines were cultured under the degressive oxygen concentration. Cell doubling time was calculated by cell counting method. Chemo-resistance ability of cells was tested by MTT assay. Irradiation tolerance of cells was evaluated by colony forming method. Cell cycle distribution was tested with flow cytometry. Invasive ability was tested by Transwell method. The expression levels of GLUT-1 and HIF-1α were detected by using Western blot. MNK45/HYP cells successfully survived under the 1% concentration of oxygen and its cell doubling time was 35.01±1.02 h, while that of MNK45 was 27.35±0.83 h (P<0.01). The percentage of MNK45/HYP cells in G(0)/G(1) stage was (58.3±6.1)%, and that of MNK45 cells was (42.2±6.0)% (P<0.05). Comparing with the parental cells MNK45, drug resistance indexes of 5-Fu, PTX, OXA, Sn38, GEM and VP16 in MNK45/HYP cells were respectively 5.3, 1.3, 3.6, 2.2, 4.8 and 4.4. Colony forming ability of MNK45/HYP cells after irradiation was also significantly higher than MNK45 cells. The invasive number of MNK45/HYP cells was 107.7±17.5, while that of MNK45 cells was 59.0±9.9. The expression levels of GLUT-1 and HIF-1α in MNK45/HYP cells were significantly higher than those in MNK45 cells. MNK45/HYP cells hold biological characteristics of hypoxia tumor with good tolerance to chronic hypoxia, and can be used for the research of solid tumor under chronic hypoxia condition.

ObjectiveTo investigate the social support status and influencing factors of schizophrenics in remission in Northeast Sichuan， and to provide ideas for improving their social support. MethodsFrom May to September 2020， a total of 533 patients who met the diagnosis criteria of the International Classification of Diseases， tenth edition （ICD-10） for schizophrenics in remission at the mental health institutions in Guangyuan， Bazhong and Dazhou cities were selected for the survey， and patients were assessed by self-made demographic and clinical data inventory and Social Support Rating Scale （SSRS）. Then the social support status of schizophrenic in remission and influencing factors were analyzed， meantime， the impact of the second round reimbursement policy of medical insurance benefits on their social support was addressed particularly. Results①The SSRS total score， objective support， subjective support， and utilization of support scores of schizophrenics in remission were lower than those of the national norm （t=5.065~30.382， P<0.01）. ②Univariate analysis showed that SSRS score was relatively high among patients with female gender （t=-3.632）， retired status （F=5.951）， married status （F=5.951）， spouse as primary caregiver （F=23.841）， annual household income >5 000 yuan （F=15.892）， patient's economic income （t=4.083）， and outpatient or online follow-up （F=3.954）， with statistically significant differences （P<0.05 or 0.01）. ③The total and dimensional scores of SSRS in patients with access to the second round medical insurance reimbursement were significantly higher than those without （t=10.195~25.103， P<0.01）. ④Multiple linear regression analysis denoted that gender， work status， marital status， primary caregivers， annual family income， economic income， follow-up visits and the second round medical insurance reimbursement were the factors influencing social support status of schizophrenics in remission （β=0.201~2.115， P<0.05 or 0.01）. ConclusionThe social support of schizophrenics in remission in Northeast Sichuan is below the national average， furthermore， their social support levels are affected by the gender， work status， marital status， primary caregivers， annual family income， economic income， follow-up visits and the second round medical insurance reimbursement， and the second round medical insurance reimbursement may ameliorate the social support status of patients.

In order to investigate the effects of short hairpin RNA (shRNA) on the expression of Survivin, cell cycle and cell proliferation in MCF-7 cells, using a pEGFP vector which contained a U6 promoter shRNA plasmid targeted against survivin was constructed and transfected into MCF-7 cells. The change of the expression of Survivin and cell proliferation rates were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and MTT methods respectively. The change of cell cycle after transfection was analyzed by flow cytometry. The results indicated that the recombinant plasmid containing Survivin shRNA was constructed successfully, which could suppress the expression of Survivin at mRNA and protein level. The growth of MCF-7 cells was arrested in G1 phase of the cell cycle and the proliferation activity was suppressed after transfection. It was concluded that Survivin shRNA plasmid could knock down the expression of Survivin in MCF-7 cells specifically. In addition, Survivin shRNA plasmid could lead to G1 arrest and inhibit the proliferation of MCF-7 cells, which suggested that Survivin shRNA might be used as a new therapeutic method for breast cancer.

Radiation-induced brain injury is a neurological injury caused by radiation therapy of head and neck tumors. The pathogenesis is still unclear. It is hypothesized that immune cells play an important role in radiation-induced brain injury. The excessive activation of microglia in the central nervous system and the migration of peripheral immune cells into the brain collectively promote the incidence and development of radiation-induced brain injury. In this article, the immunological mechanism underlying the radiation-induced brain injury was reviewed.

Objective:To investigate the changes of default network functional connectivity (FC) in resting state of patients with insomnia disorder (ID).Methods:Fifty-six patients with insomnia disorder and fifty healthy controls were recruited. All subjects were assessed with Pittsburgh sleep quality index (PSQI), insomnia severity index (ISI), Epworth sleepiness score (ESS) and Hamilton depression scale (HAMD-17). All subjects were scanned with resting state functional magnetic resonance imaging (rs-fMRI). SPM12 and CONN18b were used to preprocess rs-fMRI data on MATLAB (R2013b).The medial superior frontal gyrus was defined as the seed point, and the differences in the functional connection strength of the two groups of subjects were compared. Pearson correlation analysis was performed between the FC value of the brain area with statistical significance and scores of PSQI and ISI.Results:(1)FC analysis showed that compared with the control group, patients with ID had abnormal default mode network (DMN) connection, as follows: FC of left medial superior frontal gyrus and left central anterior gyrus (MNI: x, y, z=-30, -15, 51) and anterior cingulate gyrus (MNI: x, y, z=-6, 24, 36), FC of right medial forehead between the last gyrus and the left central anterior gyrus (MNI: x, y, z=-48, -6, 48), FC of left anterior cuneiform and the left central back (MNI: x, y, z=-54, -18, 54) and left superior occipital gyrus (MNI: x, y, z=-21, -69, 30), FC of right precuneus and left central posterior gyrus (MNI: x, y, z=-60, -21, 48) was enhanced. The FC of left anterior cuneiform lobe and the right middle frontal gyrus (MNI: x, y, z=42, 33, 42) and the right angular gyrus (MNI: x, y, z=54, -51, 45), FC of right precuneus and left inferior temporal gyrus (MNI: x, y, z=-51, -12, -42) was weakened. (2)With the left medial superior frontal gyrus as the seed point, FC values in anterior cingulate gyrus ( r=0.451, 0.338, both P<0.01) and left anterior central gyrus ( r=0.324, 0.402, both P<0.05) were positively correlated with PSQI and ISI scores. With the right precuneus as the seed point, FC value of left posterior central gyrus was positively correlated with PSQI( r=0.333, P=0.013) and ISI scores( r=0.418, P=0.008), while FC value of left inferior temporal gyrus was negatively correlated with PSQI( r=-0.662, P=0.001) and ISI scores( r=-0.402, P<0.01).With the left precuneus as the seed point, FC value of left superior occipital gyrus was positively correlated with PSQI( r=0.438, P=0.001) and ISI scores( r=0.495, P=0.011). Conclusion:Patients with ID may have changes in the functional connection of multiple networks. The decrease of FC in DMN may be one of the potential causes of insomnia. The increase in FC between DMN and the visuospatial attention network may be the core of the mechanism of damage to the brain function network of insomnia link.

The benefit achieved by concurrent chemoradiotherapy (CCR) and sequential chemoradiotherapy (SCR) vs radiotherapy (RT) alone for patients with stage II-IVa nasopharyngeal carcinoma (NPC) was compared. A total of 113 patients with stage II-IV a NPC were allotted into CCR group (n=38), SCR group (n=36) and RT alone group (n=39). All patients were irradiated with the same RT technique to ≥66 Gy at 2 Gy per fraction, conventional 5 fractions/week in all groups. The CCR group received concurrent chemotherapy of weekly cisplatin for 7 weeks, and the SCR group received neoadjuvant and (or) adjuvant chemotherapy. The results showed that the 3- and 5-year overall survival rate was significantly higher in CCR group than in RT alone group (92.16% vs 61.54%, 81.58% vs 51.28%, P<0.005). The median survival time was significantly longer in CCR group than in RT alone group (67.8 months vs 52.7 months, P<0.005). It was concluded that CCR could significantly improve overall survival rate, progression-free survival rate, and median survival time when compared with RT alone.

The inhibitory effects of Endostar in combination with radiotherapy in BALB/c nude mice model of human CNE2 nasopharyngeal carcinoma and the mechanism were investigated. In nude mice model of CNE2 nasopharyngeal carcinoma, the inhibitory rate and the sensitizing enhancement ratio (E/O) were calculated according to the tumor volumes in different groups. The expression of microvascular density (MVD) in tumor tissues was examined by using immunohistochemistry staining. The transcription of VEGF gene was detected by using RT-PCR. The inhibitory rate in Endostar+ radiotherapy group was higher than in other groups. In Endostar+radiotherapy group, the tumor volume was significantly decreased and the E/O ratio was 2.335, suggesting that Endostar could be a radiosensitizer. The expression of MVD of tumor tissues in Endostar+radiotherapy group was reduced significantly. The expression of the MVD in treatment groups was significantly different from that in control group (P<0.05). Compared to other groups, VEGF mRNA expression in Endostar+radiotherapy group was decreased remarkably. Endostar in combination with radiotherapy significantly inhibited the growth of CNE2 tumor. The combination therapy decreased the expression of VEGF, and inhibited tumor angiogenesis and proliferation. When combined with radiotherapy, Endostar acted as a radiosensitizer.

Objective To understand the status of the life mcaning among medical students.Methods Totally 300 students in our school were measured by the scale of purpose in life test (PIL)to analyze the status and influencing factors of life meaning.The questionnaire data were analyzed by using two independent samples t-test,One-way ANOVA and multiple linear regression.Results The average score of the life meaning survey of medical students was 84,the life goal and life value dimension scores were relatively high and the life attitude and life independent dimension scores were low.Meanwhile,the life mean in scores were higher in senior students than in junior students ( P =0.003 ),higher in undergraduate students than in college students (P =0.021 ),higher in students from urban cities than in students from rural areas ( P =0.004),higher in student leaders than in non student leaders (P =0.001 ),higher in students liking their majors than in students disliking their majors (P =0.003).Conclusions The formation of medical students' life meaning is influenced by a variety of factors.Educators need to seize the important period of students' growth and launch some targeted educational activities.Meanwhile,in order to enhance the medical students' life meaning,it is also necessary to consolidate the professional education,increase students' self-identity and guide them to correctlv view social problems.

Aimed at the current plight of medical students' professionalism education,such as ignoring the top -level design and the overall plan but emphasizing practice,ignoring the permeability of professional spirit but emphasizing the impartation of professional knowledge,ignoring humanities but emphasizing professional issues in curriculum setting,Capital Medical University advocated the all-dimensional education philosophy implenented by all staff through the whole process,made top-level design scientifically for medical students' professionalism education.The university strengthened professionalism through teaching,permeated professionalism through a series of educational activities,consolidated professionalism through clinical practice,and thus to strengthen the cultivation of medical students' professionalism and realize scientific education by all staff and throughout the whole process.

Objective To evaluate dose variations induced by gravity of multi-leaf collimator to provide references for clinical intensity-modulated radiotherapy.Methods Two-dimensional dose distributions in the central plane of IMRT fields were measured by use of a 2D ion chamber array.All measurements were repeated at two collimator angles (C=0 and 90°),for each of the following gantry angles:G=0 and 270°.Comparisons were made to dose distributions generated at G=0°and their differences were analyzed using gamma index analysis (3％/3 mm and 1％/1 mm).Results Under the radiation field of 10 cm×10 cm,the gamma passing rate was higher than 99％ for 3％ 3 mm anch close to 95％ for 1％/1mm Under a 3％/3mm error standard,the average matching rate for step & shoot fields was (96.46±0.33)％ and for DMLC fields was (94.67±0.54)％ at C=0°;The average matching rate for step & shoot fields was (94.59±0.47)％ and for DMLC fields was (92.60±0.52)％ at C=90°.Under a 1％/1mm error standard,the average matching rate for step & shoot fields was (89.83 ±1.06)％ and for DMLC fields was (85.84±0.57)％ at C=0°;The average matching rate for step & shoot fields was (86.91 ±1.71)％ and for DMLC fields was (83.89±0.69)％ at C=90°.Concusion MLC weight effect affects IMRT delivery dose,and DMLC fields are more sensitive to gravity than step & shoot fields.