Search

There are various magnetic field waves with frequencies ranging from mHz to thousands of Hz in the Earth's magnetosphere. These waves can be categorized into three classes depending on their period: ULF (mHz to ~ Hz), ELF (~ Hz to hundreds of Hz), and VLF (hundreds of Hz to thousands of Hz). The regular and continuous ultra-low-frequency (ULF) waves in the magneto-sphere, ranging from 1 mHz to a few Hz, are important to geomagnetic micropulsations. Recently, whistler mode waves generated by lightning and extremely low-frequency (ELF) bursts, which can be attributed to earthquakes, were detected near the surface; their frequencies range from several Hz to a few hundred Hz. The research on the characteristics of ionospheric plasma disturbance caused by the known ground-based very low frequency (VLF) transmitters, whose frequencies range from a few hundred to a few thousand Hz, is of great significance for analyzing changes in the ionospheric environment. These magnetic field waves are crucial for studying various space physical phenomena. As the wave monitoring equipment of global geomagnetic stations measures relative changes and a lack of unified calibration, they cannot conduct joint observations from high to low latitudes and unified comparative studies of the observational data from multiple sensors. The magnetoresistance sensor (ULF: 0.1 mHz–2 Hz), giant magneto-inductance sensor (ELF: 0.2 Hz–2 kHz), and coil sensor (VLF: 0.2–10 kHz) is used to develop a new generation of broadband geomagnetic wave monitors, which are placed on the geomagnetic stations in typical areas such as Mohe (high latitude), Beijing's Ming Tombs (middle latitude), and Sanya Ledong (low latitude), near the 120° meridian chain. Combined with the data of near-Earth space satellites such as FY-3E and SMILE, the observation ability of various wave phenomena in the Earth's magnetosphere will be comprehensively improved. The performance test experiment shows that the developed wave monitor can detect the fluctuating magnetic field at a particular frequency (1 mHz–10 kHz); magnetic field detection ranges of: ± 65000 nT (ULF frequency band), ± 1000 nT (ELF frequency band), and ± 100 pT (VLF band); with low nonlinear errors: ULF frequency band ≤ 0.0446 %, ELF frequency band ≤0.51 %, and VLF frequency band ≤ 1.18 %; and low noise levels: RMS ≤0.5554 nT (ULF frequency band), NPS ≤0.028 nT /√Hz (ELF frequency band), and NPS ≤0.24 pT/√Hz (VLF band). These characteristics enable the proposed broadband geomagnetic wave monitor to meet the Phase II of Chinese Meridian Project magnetic field detection requirements.

Background Deep ⁃ seated clival varied malignancies represent a surgical challenge because of complex anatomy and surgical procedures posing great risks to adjacent neurovascular structures. To investigate effects of diagnosis and treatment of clival region lesions, review experience of individualized surgical procedures and comprehensive therapy. Methods and Results A total of 56 patients with clival malignancies from July 2007 to December 2018 were included. The patients mainly presented with headache and cranial nerve paresis. After multidisciplinary consultation, radical resection were performed in 45 cases different kinds of surgical approaches including endonasal (15 cases, 33.33% ), intraoral accompanied by intraoral and endonasal combined (7 cases, 15.56%), Derome (8 cases, 17.78%), maxillary swing (9 cases, 20% ), and infratemporal (6 cases, 13.33% ) approaches were chosen according to clinical and radiographic findings, and biopsies were performed in 11 patients to confirm the pathological diagnosis. The primary pathological finding was chordoma (28 cases, 50%). Total resection was achieved in 21 cases (46.67%), and 17 cases (37.78%) underwent subtotal resection. Besides, partial resection was performed in 7 cases (15.56% ). The complications developed in 28 patients, including cranial nerve deficits (13 cases, 23.21%), cerebrospinal fluid leakage (14 cases, 25%), intracranial infection (8 cases, 14.29%), pneumonitis (2 cases, 3.57% ), postoperative hematoma (2 cases, 3.57% ), and mental disorder (1 cases, 1.79% ). Adjuvant chemoradiotherapy was provided by the oncologists depending on the pathological findings. The average follow⁃up was 59.90 months, but 8 patients (14.29%) were lost. The progression⁃free survival was achieved in 16 patients (28.57%), whereas the disease progression occurred in 13 patients (23.21%). The mortality was 33.93% (19/56). Conclusions Although malignancies occupy a larger subset of clival tumors, not all are needed to be radically resected. Our preliminary results suggest that multidisciplinary consultation is indispensable to clarify the therapeutic purpose and provide individualized surgical approaches. Postoperative comprehensive therapy may reduce the surgical complications and improve the outcomes of patients. DOI：10.3969/j.issn.1672⁃6731.2020.03.008

Objective To review experience of diagnosis, surgical procedures and comprehensive therapeutic strategies for skull base bone tumors. Methods and Results Clinical data of 76 patients with skull base bone tumors were retrospectively analyzed from September 2006 to March 2018. After preoperative assessment, different kinds of surgical approaches including endonasal, intraoral, maxillary swing, craniocervical transjugular, Derome, frontotemporal and infratemporal approaches were chosen according to clinical and radiographic findings. In comparison with 24 patients receiving the endoscopic surgery, other 52 patients were operated on under microscopic visualization. Total resection was achieved in 38 cases, and 22 patients underwent subtotal resection. In addition, 14 cases received partial resection while biopsies were performed in 2 cases to confirm histological findings. Tumor pathology included chordoma (28 cases), osteosarcoma (19 cases), chondrosarcoma (11 cases), fibrous dysplasia (8 cases), giant cell tumor of bone (5 cases), osteoblastoma (3 cases), osteochondroma (1 case), and chondromyxiod fibroma (1 case). Complications included cranial nerve deficits (19 cases), hemiparesis (3 cases), cerebrospinal fluid leakage (12 cases), intracranial infection (8 cases), pneumonitis (4 cases), and wound dehiscence (4 cases). During a 20 to 158 months follow ⁃ up, 11 cases were lost and 21 patients died in the study period. The disease ⁃ free survival was achieved in 34 cases while 10 patients experienced tumor progression. Conclusions Malignant bone tumors invading the skull base is much more common comparing with the benign lesions. Multidisciplinary consultation may improve diagnostic reliability and clarify the therapeutic purpose. Radical resection using the individualized approaches accompanied by comprehensive therapy should be considered to improve the outcomes of patients. DOI：10.3969/j.issn.1672⁃6731.2020.03.007

Due to exposure to air during rolling processes, a layer of oxide scale always coats the surface of the hot-rolled steel plates. During the subsequent cooling processes, the FeO in the oxide scale undergoes a eutectic reaction. The formation of a lamellar structure (Fe+Fe3O4) during this reaction is influenced by different cooling methods. The addition of alloying elements, however, also affects the eutectic reaction. The final oxide scale, hence, varieswith different compositions. For 700-MPa grade high strength steels, poor control of iron oxide scale is detrimental to the surface quality; such surface defects as iron oxide scale shedding, surface red rust, pit, are incurred. These defects, however, affect the overall performance of the steel. Consequently, the improvement of the surface quality of hot-rolled steel by controlling the iron oxide scale, without compromising the mechanical properties, has attracted the interest of many researchers. In this paper, the effect of cooling temperature and cooling rate on the structural transformation of tertiary oxide scale during hot-rolling was studied. A sample of 700 L steel grade was used. The study was carried out by the thermogravimetric analysis (TGA). The results show a "nose temperature" range of 450‒500 ℃ for the 700 L eutectoid transformation. The FeO shows the shortest incubation period of eutectoid transformation, hence, is prone to eutectoid transformation, forminga large number of eutectoid phase (Fe+Fe3O4). Addition of alloying elements such as manganese (Mg), niobium (Nb), and titanium (Ti) to the 700 L steel lead to grain refinement in the steel. It also increases the amount of diffusion channel of ions that participate in the eutectoid phase transformation. Consequently, the eutectoid transformation is delayed, and the eutectoid “C” curve shifts to the left. This is comparableto the eutectoid transformation rule of oxide scale on the surface of other steel grades.

Objective To summarize the diagnosis and treatment of refractory brain metastases and leptomeningeal metastases from small cell lung cancer (SCLC). Methods and Results An extensive stage SCLC male patient (44⁃year⁃old) with diffuse parenchymal meningeal metastases and large volume brain metastasis was treated with muti⁃disciplinary team (MDT), namely precise helical tomotherapy with concurrent temozolomide chemotherapy, combined with intrathecal chemotherapy and systemic therapy. After intracranial recurrent, intrathecal chemotherapy and radiotherapy were used to release the symptoms. At last, this patient died of extracranial disease and the survival time after the diagnosis of brain metastases was 16 months. Conclusions For treatment of brain or leptomeningeal metastases, comprehensive and individualized treatment are needed, and MDT treatment discussion is highly recommended. DOI：10.3969/j.issn.1672⁃6731.2019.11.011

Objective To investigate the clinical and genetic features of dentatorubral ⁃ pallidoluysian atrophy (DRPLA). Methods The trinucleotide repeats of spinocerebellar ataxia (SCA) disease genes were detected by polymerase chain reaction (PCR) initially in 388 SCA cases which included 234 cases with autosomal dominant inheritance and 154 sporadic cases. Fragment analysis with laser ⁃ induced fluorescence in capillary electrophoresis was performed for the samples with 2 bands detected by agarose gel electrophoresis (AGE). The repeat numbers of the positive or suspicious samples were verified by the pUC18⁃T vector cloning and sequencing. Results Based on the 2 methods, the cytosine⁃adenine⁃ guanine (CAG) repeat expansion of DRPLA gene was detected in one female case with mild ataxia and suspected seizure. The repeat numbers of the 2 alleles were 14 and 54 by fragment analysis, and 15 and 58 by cloning sequencing. The 2 members of her family had a history of seizure, but no obvious ataxia. The CAG repeat numbers of the other 19 cases without abnormal expansions ranged from 7 to 20, of which 9 was common. Conclusion The patient's atypical manifestations suggests that clinical variation may exist in DRPLA. Only one case of DRPLA is found in 388 SCA cases, indicating that DRPLA may be a relatively rare subtype of SCA in Chinese population. The secondary structure of DNA owing to the highly repetitive sequences will induce DNA polymerase sliding during the amplification, which will reduce the fidelity in DNA replication. This problem exists in both fragment analysis and cloning sequencing. For the latter method, the instability also appears in the process of cloning. Therefore, the repeat numbers need to be mutually verified by the 2 methods. DOI：10.3969/j.issn.1672-6731.2010.06.012

Objective: To investigate the spatial distribution of Oncomelania hupensis snail habitats at the administrative village scale in schistosomiasis-endemic areas of Hubei Province, so as to provide scientific bases for precise control of O. hupensis snails in the province., Methods: Data regarding snail distribution at the village level in Hubei Province in 2017 were collected to create a spatial analysis database of snail distribution in Hubei Province. The spatial aggregations of O. hupensis distribution were analyzed using Moran's I index and Local Moran's I index. In addition, the distances from schistosomiasis-endemic villages to the Yangtze River were captured using the software ArcGIS 13.0, and their correlations with area of snail habitats were examined with the Spearman correlation method., Results: O. hupensis snails were mainly distributed in 5 450 endemic villages from 63 counties of 13 cities in Hubei Province in 2017. The global spatial autocorrelation analysis showed spatial aggregations in the areas of historically accumulated snail habitats, current areas of snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment (all Z Scores > 0, all P values < 0.05), and no spatial aggregation was seen in the areas of snail habitats in hilly areas ( Z Score > 0, P > 0.05). There were four types of spatial distribution of historically accumulated areas of snail habitats, areas of current snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment, including the high-high type (H-H type), high-low type (H-L type), low-high type (L-H type) and random distribution type, and a high percentage of the H-H type was found. There were 340, 125 and 110 endemic villages with the H-H type of areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment, and these villages were mainly concentrated in Wuhan and Jingzhou cities, with almost consistent spatial aggregation locations. There were 319 endemic villages with the H-H type of distribution of snail habitats inside the embankment, which were mainly distributed in Jingzhou, Xiaogan and Huangshi cities. In addition, the areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment negatively correlated with the distance from the endemic villages to the Yangtze River ( r = -0.094, P < 0.01; r = -0.225, P < 0.01; r = -0.177, P < 0.01)., Conclusions: The clustering areas of snail habitats along the Yangtze River Basin, notably the villages near the Yangtze River are key regions for snail monitoring and control in Hubei Province.

Objective: To evaluate the effect of clinical pathway (CP) on the implementation of advanced schistosomiasis patients with ascites., Methods: Totally 1 129 cases of advanced schistosomiasis patients with ascites but without other complications were selected randomly from the Performance Evaluation and Management System for Medical Treatment of Advanced Schistosomiasis Patients in Hubei Province from year 2011 to 2013. Among the patients, 754 cases were treated by CP (CP group), and 375 cases were treated with traditional methods (NCP group), and the hospitalization days, hospitalization expenses, medicine proportions, treatment outcomes and degrees of satisfaction and health knowledge rates of the two groups were compared. Meanwhile, the variation of CP was calculated., Results: The average length of hospital days of the CP group and NCP group were (13.85 ± 5.60) d and (17.92 ± 5.80) d, respectively, and the average hospitalization costs of the two groups were (4 699.14 ± 1 520.59) Yuan and (5 692.01 ± 1 616.66) Yuan, respectively, both the differences were statistically significant (both P ＜ 0.05). Also the hospitalization cost structures of the two groups were remarkably different, the composition ratios of the inspection fee and accommodation fee in the CP group were lower than those in the NCP group, but the constituent ratios of the examination fee, diagnosis and treatment fee, drug charges and other expenses were higher than those in the NCP group (all P < 0.05). The awareness rate of health knowledge in the CP group was higher than that in the NCP group ( P < 0.05), but there were no statistically significant differences in the treatment outcome and the degree of satisfaction between the two groups (both P > 0.05). The variation rate of CP was 9.02% (68/754)., Conclusions: The implementation of CP can decrease the days of hospital stay and medical expenses, improve the awareness rate on health knowledge of the patients. The CP treatment with low variation rate is applicable to advanced schistosomiasis patients with ascites but without complications.

One hundred consecutive patients underwent laparoscopic cholecystectomy from May 1991 to February 1992 at Veterans General Hospital--Kaohsiung. Ninety-seven of them presented on an elective basis, including eight patients undergoing endoscopic sphincterotomy with extraction of common bile duct stone before laparoscopic cholecystectomy. The remaining 3 patients were operated during acute cholecystitis episode. Two patients with biliary injuries during laparoscopic cholecystectomy were converted to laparotomy, with a conversion rate of 2%. Intraoperative cystic cholangiogram was done selectively in 7 patients. Major complications occurred in 3 patients, including two biliary injuries and one residual CBD stone. Minor complications of wound infection were found in 7 patients. The overall morbidity rate was 10%. No operative mortality was found. Mean operation time was 112 minutes and mean blood loss was 90 ml. The mean hospital stay (3.1 days) and the mean time of returning to normal activity (14.7 days) were longer than those of Western series, but were shorter than those of open cholecystectomy. Laparoscopic cholecystectomy is a safe and effective procedure that can be performed with minimal risk. However, the importance of accurate preoperative screening and surgical experience should be emphasized for this new procedure. In patients with gall stone plus CBD stone, combined endoscopic sphincterotomy with extraction of CBD stone and laparoscopic cholecystectomy may offer a new therapeutic approach but the long term effect of endoscopic sphincterotomy needs further evaluation.

A total of 4056 consecutive patients operated for benign biliary tract disease between January 1983 and June 1990 were reviewed retrospectively. There were 71 in-hospital deaths, representing 1.75% of morality rate. Cholecystectomy was performed in 2275 patients; common bile duct exploration was carried out in 1494, with operative mortality rates of 0.4% and 3.1% respectively. Sepsis was the leading cause of mortality. The second common cause of death was hepatic failure, and respiratory failure the third. Cardiovascular problems accounted for 11.3% of death, which was much lower than reports from western series. Other causes of mortality included hypovolemic shock, anaphylactic shock, epilepsy and hypoglycemia. Of the total 4056 patients, 28.5% underwent emergency surgery. The mortality rate for emergency surgery was 3.6 times higher than for those who underwent elective operations (p less than 0.005) Significantly higher mortality rates were also seen for those aged over 70 years and of male gender. Because the mortality rate of patients who underwent emergency operation due to acute inflammatory or obstructive complications were much higher than that of elective operation group, we suggested early surgical intervention for the symptomatic patients before complications occurred.