ObjectiveTo explore the correlation among knee hyperextension angle, lower limb joints kinematics parameters and the activation of main muscles of lower limb in stroke hemiplegic patients with knee hyperextension during walking. MethodsFrom August, 2020 to September, 2021, 24 stroke hemiplegic patients with knee hyperextension and 24 healthy subjects matched with sex, age, height and body mass with knee hyperextension were analyzed with three-dimensional gait analysis system and the wireless surface electromyography acquisition system, to record the range of motion of pelvis, hip, knee and ankle joints in sagittal plane, and the activation of bilateral gluteus maximus, biceps femoris, vastus medialis and gastrocnemius medialis. ResultsAs the maximum of knee hyperextension, range of motion of the joints in sagittal plane and the activation of the muscles were different between the patients and the healthy subjects during the single-support phase of walking (|t| > 3.080, P < 0.01), and the maximum of knee hyperextension correlated with the activation of gluteus maximus in the patients (r = -0.532, P < 0.01), and the range of motion of ankle plantar flexion in both the patients and the healthy subjects (r > 0.686, P < 0.001). ConclusionThe correction for knee hyperextension gait in stroke hemiplegic patients may not only need to pay attention to knee joint control, but also need further treatment of ankle control and hip muscle function.

Objective:To investigate the clinical efficacy and prognosis of simultaneous resection of synchronous colorectal liver metastasis in patients admitted in different phases.Methods:The retrospective cohort study was conducted. The clinicopathological data of 346 patients who underwent simultaneous resection of synchronous colorectal liver metastasis in the First Affiliated Hospital of Naval Medical University (Changhai Hospital of Shanghai) from January 2000 to April 2021 were collected. There were 217 males and 129 females, aged (58±12)years. Patients under-went simultaneous resection of synchronous colorectal liver metastasis. Observation indicators: (1) clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (2) surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (3) analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Follow-up was conducted using telephone interview or outpatient examination to detect survival of patients. The follow-up was performed once every 3 months, including blood routine test, liver and kidney function test, car-cinoembryonic antigen (CEA) test, CA19-9 test, abdominal B-ultrasound examination, and once every 6 months, including chest computed tomography (CT) plain scan, liver magnetic resonance imaging (MRI) and/or CT enhanced scan, abdominal or pelvic MRI and/or CT enhanced scan, within postoperative 2 year. The follow-up was performed once every 6?12 months within postoperative 2?5 years including above reexaminations. Electronic colonoscopy was performed once a year after operation. The follow-up was up to November 12, 2021. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distuibution were represented as M(range). Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. Kaplan-Meier method was used to calculate survival rates and draw survival curves, and Log-Rank test was used to conduct survival analysis. Results:(1) Clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 59 cases underwent simultaneous resection within 2000?2010 and 287 cases underwent simultaneous resection within 2011?2021. The gender (males and females), cases with or without fundamental diseases, cases with the number of lymph nodes harvested in primary lesion as <12 or ≥12, the tumor diameter of primary lesion, the tumor diameter of liver metastasis lesion, the number of liver metastasis lesions, cases with or without preoperative treatment, cases with or without postoperative treatment, cases with adjuvant therapy as perioperative treatment, surgery or other treatment were 47, 12, 36, 23, 19, 40, (5.5±2.4)cm, (2.1±0.7)cm, 1.6±0.5, 59, 0, 16, 16, 0, 16, 43 in patients admitted in 2000?2010, respectively. The above indicators in patients admitted in 2011?2021 were 170, 117, 121, 166, 58, 229, (4.2±2.0)cm, (3.0±2.0)cm, 1.9±1.4, 208, 79, 34, 235, 74, 29, 184, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=8.73, 7.02, 4.07, t= 4.40, ?6.04, ?3.10, χ2=21.05, 28.82, 26.68, P<0.05). (2) Surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Cases with surgical methods as complete open surgery or laparoscopy combined with open surgery, the operation time, time to postoperative initial liquid food intake, cases with or without postoperative complications, cases with postoperative duration of hospital stay as ≤10 days or >10 days were 58, 1, (281±57)minutes, (5±1)days, 33, 26, 14, 45 in patients admitted in 2000?2010, respec-tively. The above indicators in patients admitted in 2011?2021 were 140, 147, (261±82)minutes, (3±1)days, 233, 54, 198, 89, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=49.04, t=2.24, 7.53, χ2=17.56, 26.02, P<0.05). There was no death in the 346 patients. (3) Analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 295 cases were followed up for 47(range, 1?108)months. Of the 29 patients admitted in 2000?2010 who were followed up, there were 27 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2000?2010 were 18.0 months (95% confidence interval as 12.7?23.3 months), 82.8%, 11.5%, 3.8%, 53.6%, 8.3%, 4.2%, respec-tively. Of the 266 patients admitted in 2011?2021 who were followed up, there were 109 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2011?2021 were 54.0 months (95% confidence interval as 38.1?70.4 months), 93.3%, 61.8%, 47.0%, 68.2%, 33.7%, 28.3%, respectively. There were significant differences in overall survival rate and disease free survival rate between patients admitted in 2000?2010 and 2011?2021 ( χ2=47.57, 9.17, P<0.05). Conclusions:With the increase of the operation volume of simultaneous resection of synchronous colorectal liver metastasis, the operation time, time to postoperative initial liquid food intake, postoperative duration of hospital stay and postoperative complications have significantly decreased, while the overall survival rate and disease free survival rate have significantly increased.

Objective:To analyze the clinical characteristics in patients with persistent positive pharyngeal swab of 2019 novel coronavirus Omicron variant and results of nucleic acid testing of anal swabs to provide basis for prevention and control measures.Methods:This study included 93 patients whose pharyngeal swab nucleic acid test were persistent positive and admitted to the ward of Daping Hospital in the National Exhibition and Convention Center (Shanghai) Makeshift Hospital from May 1 to May 24, 2022. The gender, age, underlying diseases, vaccination status, clinical symptoms, interval between infection onset and anal sampling, length of hospital stay, the nucleic acid test result of pharyngeal swabs and anal swabs and the time turning negative were collected and analyzed.Results:The age of 93 patients ranged from 8 to 72 years old with a median of (46.0±16.0) years old. Among them, 30 cases (32.3%) were male and 63 cases (67.7%) were female. Sixty-five patients (69.9%) received 2-3 shots of vaccine, 2 patients (2.1%) received 1 shot, and 26 patients (28.0%) did not receive any vaccination. Twenty patients (21.5%) had underlying diseases, of which hypertension (13 cases, 14.0%) and type 2 diabetes mellitus (6 cases, 6.5%) were the most common. Twenty-four patients (25.8%) had asymptomatic infection and the rest (69 cases, 74.2%) had mild symptoms. Cough (50 cases, 53.8%) and sore throat (28 cases, 30.1%) were the most common clinical manifestations of the upper respiratory tract in these patients. Only 6 patients (6.5%) had gastrointestinal symptoms (including diarrhea in 5 patients and diarrhea with vomiting in 1 patient). Pharyngeal and anal swabs were collected simultaneously from all 93 patients at 8-16th days [(11.55±2.27) days] after 2019 novel coronavirus Omicron variant infection. The pharyngeal swabs were positive in 79 patients (85.0%) and the anal swabs were positive in 5 patients (5.4%). The time of pharyngeal swabs turning negative was (14.7±2.9) days, and that of anal swab turning positive was (14.2±1.9) days. The median length of hospital stay was (16.7±2.9) days.Conclusions:In patients with persistent positive nucleic acid of the 2019 novel coronavirus Omicron variant, there were more mild infection than asymptomatic. The upper respiratory tract symptoms such as cough and sore throat were the most. The likelihood of transmission of 2019 novel coronavirus Omicron variant through the digestive tract may be low. The correlation between gastrointestinal symptoms and 2019 novel coronavirus Omicron variant RNA in the digestive tract is uncertain.

Objective:To compare the efficacy of 3D navigation versus C-arm fluoroscopy for placement of percutaneous double-segment long sacroiliac screws in the treatment of injury to the posterior pelvic ring.Methods:A retrospective study was conducted in the 48 patients with pelvic fracture who had been treated surgically from February 2015 to October 2020 at Department of Orthopaedics, General Hospital of Central Command of PLA. The patients were divided into a navigation group and a fluoroscopy group according to their different auxiliary ways to assist screw placement. In the navigation group of 27 patients, there were 19 males and 8 females, with an age of (45.5±7.4) years; in the fluoroscopy group of 21 patients, there were 14 males and 7 females, with an age of (44.1±10.1) years. The 2 groups were compared in terms of placement time for each screw, fluoroscopy time for each screw, adjustments of guide wire, accuracy of screw position, quality of fracture reduction, fracture union time, pelvic function, and postoperative complications.Results:The 2 groups were comparable because there was no significant difference between them in the preoperative general data ( P>0.05). The placement time for each screw [(12.7±2.2) min], fluoroscopy time for each screw [(40.7±9.3) s] and adjustments of guide wire [1 (0,1) time] in the navigation group were significantly less than those in the fluoroscopy group [(23.7±3.6) min, (71.4±14.1)s and 5 (4,6) times] (all P<0.05); the assessment of screw placement in the former (49 excellent, 4 good and one poor cases) was significantly better than that in the latter (29 excellent, 8 good and 5 poor cases) ( P<0.05). The 48 patients were followed up for 8 to 25 months (mean, 13.1 months). There were no significant differences between the 2 groups in fracture union time, quality of fracture reduction or Majeed scores for the pelvic function (all P>0.05).Symptoms of injury to the L5 nerve root were observed in one patient in the fluoroscopy group; none of the patients reported postoperative complications like wound infection, screw loosening or breaking. Conclusions:Compared with C-arm fluoroscopy, 3D navigation may better assist placement of percutaneous double-segment long sacroiliac screws in the treatment of injury to the posterior pelvic ring, because 3D navigation can significantly shorten the time for screw placement and the fluoroscopy time for screw placement, reduce adjustments of guide wire, and improve accuracy of screw placement.

Objective:To evaluate the clinical results of miniplates combined with reconstruction plate in treating comminuted posterior wall acetabular fractures.Methods:A retrospective case series study was conducted for 27 patients with comminuted posterior wall acetabular fractures treated in General Hospital of Central Theatre Command of PLA from October 2015 to June 2019. There were 18 males and 9 females, at age of 23-61 years［（45.9±10.9）years］. All patients were treated by using miniplates combined with the reconstruction plate. The operation time, intraoperative blood loss, intraoperative blood transfusion, length of hospital stay and time of fracture healing were recorded. The reduction quality was evaluated according to Matta radiographic standard at 2 days postoperatively. The modified Merle D'Aubigné-Postel score was adopted to evaluate the hip function at 3, 6 months postoperatively and the final follow-up. Postoperative complications were observed, and heterotopic ossification was assessed by Brooker grading standard.Results:All patients were followed up for 12-48 months［36（24, 36）months］. The operation time was 123-242 minutes［（165.4±29.8）minutes］; the intraoperative blood loss was 170-550 ml［（358.3±111.3）ml］; nine patients required intraoperative blood transfusion of 300-500 ml［（377.8±66.7）ml］. The length of hospital stay was 12-29 days［（21.4±4.7）days］. The fracture healing time was 12-24 weeks［（16.3±3.0）weeks］. According to Matta radiographic standard, the reduction quality was excellent in 21 patients, good in 3 and poor in 3 at 2 days postoperatively, with the excellent rate of 89%. The modified Merle D'Aubigné-Postel score was 9-16 points［（13.1±1.9）points］at 3 months postoperatively, was 10-18 points［（15.4±2.0）points］at 6 months postoperatively, and was 12-18 points［（16.9±1.8）points］at last follow-up（ P<0.01）. The modified Merle D'Aubigné-Postel score between 3 months and 6 months was significantly different（ P<0.01）, and the difference between 6 months and the follow-up was statistically significant（ P<0.01）. The modified Merle D'Aubigné-Postel score was graded as excellent in 0 patient, good in 7, fair in 11 and poor in 9 at 3 months postoperatively, with the excellent rate of 26%; graded as excellent in 3 patients, good in 19, fair in 2 and poor in 3 at 6 months postoperatively, with the excellent rate of 81%; graded as excellent in 18 patients, good in 5, fair in 3 and poor in 1 at the last follow-up, with the excellent rate of 85%（ P<0.01）. No iatrogenic sciatic nerve injury, deep vein thrombosis or wound infection occurred after operation. No hardware loosening or loss of reduction occurred during the follow-up. The post-traumatic arthritis was identified in 2 patients. The avascular necrosis of femoral head was observed in 1 patient and thereafter underwent total hip replacement. The heterotopic ossification occurred in 3 patients, among which 2 patients were graded as Brooker class I and 1 as class II, but there was no adverse effect on hip function. Conclusions:Miniplates combined with reconstruction plate in the treatment of comminuted posterior wall acetabular fractures have reliable fixation effect and attain good reduction, high fracture healing rate, less complications and satisfactory functional recovery.

OBJECTIVE： To provide reference for improving emergency capacity of the hospital pharmacy department in response to the novel coronavirus pneumonia （COVID-19） epidemic. METHODS ：According to the related regulations and requirements of Law of the People ’s Republic of China on the Prevention and Control of Infectious Diseases ，combined with the situation of COVID- 19 epidemic prevention and control ，and management experience of relevant hospitals ，on the basis of in-depth analysis of drug supply and quality assurance ，drug dispensing management ，provision of clinical pharmaceutical services and other related material support of hospital pharmacy department，integrated emergency management model was constructed for COVID- 19 epidemic prevention and control ，and the precautions and response measures of each link were sorted out. RESULTS ：Integruted emergency management mode for COVID-19 epidemic prevention and control in hospital pharmacy department included but was not limited to human resource management，drug and disinfection products supply management （mainly including key treatment drugs and disinfection product list formulation，control，inventory increase ，etc.）；drug dispensing management （mainly including prescription ，pharmacy window ， planning quantitative reserve ， drug return ， etc.）；clinical pharmaceutical care management （mainly including providing pharmaceutical information support ，online pharmaceutical service ，monitoring drug safety ，etc.）；personnel protection and disinfection （mainly including personnel protection ，environment and window ，equipment and container ，paper prescription disinfection，etc.）；special management of donated drugs ；prevention and control knowledge training ；pharmaceutical education and scientific research management ，etc. CONCLUSIONS ：The integrated emergency management model for epidemic prevention and control is helpful for hospital pharmacy to manage public health emergencies. During the outbreak of COVID- 19，hospital pharmacy department should start integrated emergency management mode for epidemic prevention and control ，strengthen the risk control of each link ，and play a good role in the key functional departments in the special period.

Objective:To explore the predictive factors of pathological complete response (pCR) after neoadjuvant chemoradiotherapy for middle-low rectal cancer.Methods:A case-control study was conducted. The inclusion criteria were as follows: (1) colonoscopy, digital examination or magnetic resonance imaging (MRI) showed a distance from the lower edge of the tumor to the dentate line of no more than 10 cm; (2) complete clinicopathological data were available; (3) preoperative biopsy revealed adenocarcinoma; (4) preoperative pelvic MRI or endorectal ultrasonography was performed; (5) no distant metastasis was found. Exclusion criteria: (1) preoperative radiotherapy and chemotherapy were not administrated according to the standard; (2) simultaneous multiple primary cancer and familial adenomatous polyposis were observed. According to the above criteria, clinicopathological data of 245 patients with middle-low rectal cancer undergoing preoperative neoadjuvant chemoradiotherapy in Changhai Hospital of Navy Medical University from January 2012 to December 2019 were retrospectively collected. Univariate analysis and multivariate logistic analysis were used to identify the clinical factors predicting pCR. pCR is defined as complete disappearance of cancer cells under the microscope in cancer specimens (including lymph nodes) after neoadjuvant chemoradiotherapy.Results:A total of 72 patients with pCR were enrolled in this study. Univariate analysis showed that preoperative T stage, tumor circumference, tumor morphology, carbohydrate antigen (CA) 19-9, interval between the end of neoadjuvant therapy and operation were associated with pCR (all P<0.05). The above 5 variables were included in multivariate logistic analysis and the results revealed that the T stage (OR=5.743, 95% CI: 2.416-13.648, P<0.001), tumor circumference (OR=7.754, 95% CI: 3.822-15.733, P<0.001), tumor morphology (OR=0.264, 95% CI: 0.089-0.786, P=0.017) and the interval between the end of neoadjuvant therapy and operation (OR=0.303, 95% CI: 0.147-0.625, P=0.001) were independent predictive factors of pCR, while CA 19-9 level was not an independent factor (OR=1.873, 95% CI:0.372-9.436, P=0.447). Conclusion:By knowing the clinical features of preoperative T stage, tumor circumference, tumor morphology and the interval between neoadjuvant chemoradiotherapy and operation, patients with higher likelyhood of pCR after neoadjuvant chemoradiotherapy may be identified.

Objective:To explore the predictive factors of pathological complete response (pCR) after neoadjuvant chemoradiotherapy for middle-low rectal cancer.Methods:A case-control study was conducted. The inclusion criteria were as follows: (1) colonoscopy, digital examination or magnetic resonance imaging (MRI) showed a distance from the lower edge of the tumor to the dentate line of no more than 10 cm; (2) complete clinicopathological data were available; (3) preoperative biopsy revealed adenocarcinoma; (4) preoperative pelvic MRI or endorectal ultrasonography was performed; (5) no distant metastasis was found. Exclusion criteria: (1) preoperative radiotherapy and chemotherapy were not administrated according to the standard; (2) simultaneous multiple primary cancer and familial adenomatous polyposis were observed. According to the above criteria, clinicopathological data of 245 patients with middle-low rectal cancer undergoing preoperative neoadjuvant chemoradiotherapy in Changhai Hospital of Navy Medical University from January 2012 to December 2019 were retrospectively collected. Univariate analysis and multivariate logistic analysis were used to identify the clinical factors predicting pCR. pCR is defined as complete disappearance of cancer cells under the microscope in cancer specimens (including lymph nodes) after neoadjuvant chemoradiotherapy.Results:A total of 72 patients with pCR were enrolled in this study. Univariate analysis showed that preoperative T stage, tumor circumference, tumor morphology, carbohydrate antigen (CA) 19-9, interval between the end of neoadjuvant therapy and operation were associated with pCR (all P<0.05). The above 5 variables were included in multivariate logistic analysis and the results revealed that the T stage (OR=5.743, 95% CI: 2.416-13.648, P<0.001), tumor circumference (OR=7.754, 95% CI: 3.822-15.733, P<0.001), tumor morphology (OR=0.264, 95% CI: 0.089-0.786, P=0.017) and the interval between the end of neoadjuvant therapy and operation (OR=0.303, 95% CI: 0.147-0.625, P=0.001) were independent predictive factors of pCR, while CA 19-9 level was not an independent factor (OR=1.873, 95% CI:0.372-9.436, P=0.447). Conclusion:By knowing the clinical features of preoperative T stage, tumor circumference, tumor morphology and the interval between neoadjuvant chemoradiotherapy and operation, patients with higher likelyhood of pCR after neoadjuvant chemoradiotherapy may be identified.

OBJECTIVE: To investigate the surgical efficacy and prognostic factors of T3NxM0 middle-low rectal cancer without neoadjuvant therapy. METHODS: Clinical data of patients with middle-low rectal cancer undergoing TME surgery with T3NxM0 confirmed by postoperative pathology at Colorectal Surgery Department of Changhai Hospital from January 2008 to December 2010 were analyzed retrospectively. INCLUSION CRITERIA: (1)no preoperative neoadjuvant chemoradiotherapy (nCRT); (2) complete preoperative evaluation, including medical history, preoperative colonoscopy or digital examination, blood tumor marker examination, and imaging examination; (3) distance between tumor lower margin and anal verge was ≤ 10 cm; (4) negative circumferential resection margin (CRM-). Finally, a total of 331 patients were included in this study. According to the number of metastatic lymph node confirmed by postoperative pathology, the patients were divided into N0 group without regional lymph node metastasis (190 cases) and N+ group with regional lymph node metastasis (141 cases). The perioperative conditions, local recurrence, distant metastasis and prognostic factors were analyzed. RESULTS: Compared to N0 group in the perioperative data, N+ group had higher ratio of tumor deposit [29.8%(42/141) vs. 0, χ²=64.821, P<0.001] and vascular invasion [7.1%(10/141) vs. 0.5%(1/190),χ²=10.860, P<0.001]. There were no significant differences in tumor diameter, number of lymph nodes detected, positive nerve invasion, degree of tumor differentiation, morbidity of postoperative complication and postoperative adjuvant chemotherapy rate between the two groups (all P>0.05). The median follow-up period was 73.4 months. The merged 5-year local recurrence rate was 2.7%(9/331), 5-year distant metastasis rate was 23.3% (77/331), 5-year disease-free survival (DFS) rate was 73.4%, and 5-year overall survival (OS) rate was 77.2%. Multivariate analysis showed that lymph node metastasis (HR=3.120, 95%CI: 1.918 to 5.075, P<0.001), nerve invasion (HR=0.345, 95%CI: 0.156 to 0.760, P=0.008) and vascular invasion (HR=0.428, 95%CI: 0.189 to 0.972, P=0.043) were independent risk factors for DFS in patients with T3NxM0 rectal cancer after operation. Preoperative carcinoembryonic antigen level (HR=1.858, 95%CI:1.121 to 3.079, P=0.016), lymph node metastasis (HR=3.320, 95%CI: 1.985 to 5.553, P<0.001) and nerve invasion (HR=0.339, 95%CI: 0.156 to 0.738, P=0.006) were independent risk factors for OS in patients with T3NxM0 rectal cancer after operation. CONCLUSIONS Optimal local control rate of middle-low rectal cancer patients with T3NxM0 and CRM- can be achieved by standard TME surgery alone. For patients with preoperative elevated blood carcinoembryonic antigen level, regional lymph node metastasis, or neurovascular invasion confirmed by pathology after surgery, adjuvant chemoradiotherapy should be actively applied after surgery to improve prognosis.
Humans ; Lymph Node Excision ; Lymph Nodes ; pathology ; surgery ; Lymphatic Metastasis ; Mesocolon ; surgery ; Neoadjuvant Therapy ; Neoplasm Staging ; Proctectomy ; methods ; Prognosis ; Rectal Neoplasms ; pathology ; surgery ; Retrospective Studies

OBJECTIVE: To construct a magnetic and catalytic hairpin assembly-based platform for detection of dual membrane proteins on exosomes. METHODS: Exosomes in supernatant of breast cancer MDA-MB-231 cell culture were separated, purified and characterized. Super-resolution imaging and Western blotting were performed to confirm the expression of the membrane protein CD63 on the exosomes. Polyacrylamide gel electrophoresis was used to verify the combination of Apt-T and exosomes. Fluorescence experiments were carried out to test the feasibility of CHA nucleic acid sequence, optimize the reaction conditions, and determine the specificity of the detection platform. RESULTS: Super-resolution imaging and Western blotting showed that breast cancer MDA-MB-231 cell-derived exosomes expressed abundant membrane protein CD63. Polyacrylamide gel electrophoresis indicated that Apt-T could recognize and bind to exosomes. The results of specificity test showed that the signal-to-noise ratio of the detection platform was 1.10±0.01 for detecting normal human breast epithelial cell-derived exosomes, and was 2.09±0.08 for breast cancer cell-derived exosomes. CONCLUSIONS Magnetic and catalytic hairpin assembly-based detection platform allows simultaneous detection of two membrane proteins expressed on exosomes and identification of the expressions of membrane proteins on exosomes from different sources.
Blotting, Western ; Exosomes ; Humans ; Magnetic Phenomena ; Membrane Proteins ; Sensitivity and Specificity