A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover.

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

[Indications and efficacy of neoadjuvant therapy for pancreatic cancer].

Pancreatic cancer has a high degree of malignancy, with a poor prognosis. Although surgical resection remains the only way to cure pancreatic cancer at present, the treatment mode has changed from "surgery priority" to "multidisciplinary cooperation" with the development of adjuvant therapy. Neoadjuvant therapy has been documented to increase the R0 resection rate of borderline resectable and locally advanced pancreatic cancer and improve the prognosis of the patients, and there has been a consensus on neoadjuvant therapy for these patients. However, there is still much controversy in the choice of neoadjuvant chemotherapy, the status of radiotherapy, imaging and pathological evaluation after neoadjuvant therapy for pancreatic cancer.

[Treatment of pancreatic diseases and prevention of infection during outbreak of 2019 coronavirus disease].

Objective: To explore the proper protective measures for pancreatic diseases treatment during the outbreak of 2019 coronavirus disease(COVID-19). Methods: Clinical data of four cases of patients that suffered COVID-19 from February 2(nd) to February 9(th), 2020 at Department of Pancreatic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology were reviewed induding 4 males and 1 female, aging of 50, 51, 46, 87 years old, respectively. After the first patients cuffed nosocomial infection of COVID-19, the general protective measures were updated.Only one patient was admitted to each room alone, with no more than one caregiver. The body temperature of care givers was measured twice a day.Primary protections were applied to all staff.The floor was sterilized using disinfectant with an effective chlorine concentration of 1 000 mg/L. The protective measures for interventional procedures were as follow. Primary protection was applied to the operators of central venipuncture catheter, percutaneous abdominal/pleural drainage, percutaneous retroperitoneal drainage, percutaneous transhepatic cholangial drainage and other surgical procedures with local anesthesia and epidural anesthesia. Secondary protection was applied to the operators of endoscopic retrograde cholangiopancreatography and surgical procedures with general anesthesia. Results: There were four patients who were diagnosed as COVID-19, of which one died of COVID-19, two were cured, and one was still in hospital for COVID-19. After the update of protective measures, no more nosocomial infection of COVID-19 occurred. Two central venipuncture catheter, three percutaneous abdominal or pleural drainage, one percutaneous retroperitoneal drainage, one percuteneous transhepatic cholecyst drainage and one open surgery with general anesthesia were performed with no infection of operators. Conclusions: The caregivers of patients are potential infection source of COVID-19. Enhanced protective measures including the management measures of caregivers can decrease the risk of nosocomial infection of COVID-19.

[Changes of surgical interventions on necrotizing pancreatitis].

Objective: To investigate the changes of surgical invitations on necrotizing pancreatitis in recent 14 years by reviewing single center data. Methods: One thousand and eighty patients with necrotizing pancreatitis who received surgical invitation were involved in the study.All the patients were treated at Department of Pancreatic Surgery,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology from January 2005 to December 2018. Six hundred and seventy-eight were males and 402 were females. The median (range) age of the study patients was 45 (20-76) years.The etiology of the disease was related to cholelithiasis in 335 cases(31.02%), hyperlipemia in 302 cases(27.96%), alcohol in 226 cases(20.93%), endoscopic retrograde cholangiopancreatography in 28 cases(2.59%), pregnancy in 50 cases(4.63%), idiopathic factors in 72 cases(6.67%) and other causes in 67 cases(6.20%). The patients were divided into two groups according to the time of admission. Group 1 included 1 475 patients that admitted from January 2005 to December 2010, and group 2 included 1 539 patients that admitted from January 2011 to December 2018. The surgical interventions, morbidity and mortality of the two group were compared, and χ(2) test was used for the statistical test. Results: Two hundred and sixty-six among the 1 080 cases were treated with drainage procedures because of the pseudocyst.One hundred and seventy-five drainage procedures were performed between January 2005 and December 2018, which account for 11.87%(175 /1 475) of all patients of necrotizing pancreatitis; 91 drainage procedures were performed between January 2011 and December 2018,which account for 5.91%(91/1 539) of all patients of necrotizing pancreatitis. Eight hundred and fourteen cases received surgical intervention for infection of necrotizing tissues. Of these cases, 410 cases received percutaneous catheter drainage(PCD) of retroperitoneal fluid or residual infection. Debridement of necrotic tissues was performed on 756 cases. Of these cases, 32 cases received minimal invasive retroperitoneal debridement with/without denotes video assistant,4 cases received transluminal endoscopic debridement, 21 cases received laparoscopic debridement, and 709 cases received open laparotic debridement.Three hundred and sixty-five cases were admitted to our institute during January 2005 to December 2010, and the other 391 cases were admitted to our institute from January 2011 to December 2018. Of the first period, all debridement were performed with open laparotic procedures. Of the second period,debridement were performed with open laparotic procedures and minimal invasive procedures. The average times of surgical invasion, morbidity of principal local complications and mortality of the two periods were 1.27 and 1.34,28.22%(103/365) and 29.92%(117/346),and 6.03%(23/365) and 6.91%(27/346), respectively. Conclusions: Minimal invasive procedures can be considered for debridement in patients with necrotizing pancreatitis in some selected conditions.The involvements of minimal invasive procedures in treatment of necrotizing pancreatitis don't decrease the morbidity of principal local complications and mortality in recent years. Rational surgical procedures and appropriate surgical timing are the keys to improve the efficacy of necrotizing pancreatitis.

[Clinicopathological significance of poorly differentiated clusters in colorectal adenocarcinoma].

Objective: To investigate the correlation between poorly differentiated clusters (PDCs) in colorectal adenocarcinomas with clinicopathological parameters and its clinicopathological significance. Methods: One hundred and eighty-three colorectal adenocarcinomas resected by radical proctocolecomy were collected at Nanjing Hospital(Nanjing First Hospital), Nanjing Medical University, from January to December 2017. There were 122 male and 61 female patients with age ranging from 42 to 89 years (mean of 68 years). Tumor diameter ranged from 2 to 14 cm (mean 4.5 cm). There were 124 colon cancers and 59 rectal cancers. The number and grade of PDCs in the colorectal adenocarcinoma were evaluated by H-E staining. The overall peritumoural inflammatory reaction was also evaluated. The relationship between PDCs and tumor grades and clinicopathological features and overall peritumoural inflammatory reaction of colorectal adenocarcinoma was analyzed. Results: Of 183 cases of colorectal adenocarcinoma, PDCs were seen in 104 cases (56.8%), of which 36 cases (19.7%) were grade 1, 28 cases (15.3%) were grade 2, and 40 cases (21.9%) were grade 3. PDCs were positively correlated with lymph node metastasis, vascular invasion, degree of differentiation, depth of invasion, and pTNM staging(P<0.05). The detection rate of PDCs in colon cancer was higher than that of rectal cancer(P<0.05). PDCs was unrelated to age, gender, tumor size, and degree of overall peritumoural inflammatory reaction (P>0.05). Among clinicopathological parameters, the grade of PDCs was correlated with lymph node metastasis and vascular invasion (higher than those without lymph node metastasis and vascular invasion, P<0.05); There was a positive correlation between the grade of PDCs and age, tumor differentiation and pTNM staging(P<0.05), and no significant difference between the grade of PDCs and gender, tumor size, tumor location, and depth of invasion was seen (P>0.05). There was no correlation between the grade of PDCs and the degree of overall peritumoural inflammatory reaction (P>0.05). Conclusions: PDC is a histological feature that predicts the aggressiveness of colorectal adenocarcinoma. Evaluation of PDC grade can better predict the biological behavior of colorectal cancer and more accurately guide the treatment and evaluate prognosis.

Complement regulatory proteins in kidneys of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis.

The complement system activation is involved in the development of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). The study aimed to investigate the expression of complement regulatory proteins (CRPs) CD46, CD55 and CD59 in kidneys of 51 AVV patients. The expression of CD46, CD55 and CD59 in kidneys was detected by immunohistochemistry and double immunofluorescence staining. The immunohistochemical examination revealed that expression of the three CRPs could be detected in the glomeruli and tubules of both AAV patients and normal controls. The expression levels of the three CRPs in glomeruli of patients with AAV were significantly lower than those of normal controls. The scores of CD46 and CD55 expression in the tubules of AAV patients were significantly lower than those of normal controls, while there was no significant difference between the scores of CD59 expression in tubules of AAV patients and those of normal controls. Among AAV patients, the expression level of CD46 in glomeruli correlated inversely with the proportion of normal glomeruli, while it correlated with tubular atrophy in renal interstitium (r = -0·305, P = 0·026; r = 0·330, P = 0·023, respectively). The expression levels of CD55 and CD59 in glomeruli correlated with the proportion of total crescents (r = 0·384, P = 0·006; r = 0·351, P = 0·011, respectively). Double immunofluorescence staining indicated that all three CRPs were expressed on endothelial cells, podocytes and mesangial cells in glomeruli. The expression levels of the three CRPs were dysregulated in kidneys of patients with AAV. The expression levels of CD46, CD55 and CD59 were associated with the severity of renal injury of AAV patients.

Feasibility of automated pancreas segmentation based on dynamic MRI.

OBJECTIVE: MRI-guided radiotherapy is particularly attractive for abdominal targets with low CT contrast. To fully utilize this modality for pancreas tracking, automated segmentation tools are needed. A hybrid gradient, region growth and shape constraint (hGReS) method to segment two-dimensional (2D) upper abdominal dynamic MRI (dMRI) is developed for this purpose. METHODS: 2D coronal dynamic MR images of two healthy volunteers were acquired with a frame rate of 5 frames per second. The regions of interest (ROIs) included the liver, pancreas and stomach. The first frame was used as the source where the centres of the ROIs were manually annotated. These centre locations were propagated to the next dMRI frame. Four-neighborhood region transfer growth was performed from these initial seeds before refinement using shape constraints. RESULTS from hGReS and two other automated segmentation methods using integrated edge detection and region growth (IER) and level set, respectively, were compared with manual contours using Dice's index (DI). RESULTS: For the first patient, the hGReS resulted in the organ segmentation accuracy as a measure by the DI (0.77) for the pancreas, superior to the level set method (0.72) and IER (0.71). The hGReS was shown to be reproducible on the second subject, achieving a DI of 0.82, 0.92 and 0.93 for the pancreas, stomach and liver, respectively. Motion trajectories derived from the hGReS were highly correlated to respiratory motion. CONCLUSION: We have shown the feasibility of automated segmentation of the pancreas anatomy on dMRI. ADVANCES IN KNOWLEDGE: Using the hybrid method improves segmentation robustness of low-contrast images.

The expression of Toll-like receptors 2, 4 and 9 in kidneys of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis.

Increasing evidence suggested that Toll-like receptors (TLRs) were critically involved in immune responses of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The current study aimed to investigate the expression of TLR-2, TLR-4 and TLR-9 in kidneys of patients with ANCA-associated vasculitis. Renal biopsy specimens were collected from 24 patients with AAV. The expression of TLR-2, TLR-4 and TLR-9 in kidneys was detected by immunohistochemistry. Double immunofluorescence staining was performed to detect the expression of TLRs on various kinds of cells. In renal specimens, immunohistochemical examination revealed that expression of TLR-2 and TLR-4 could be detected in the glomeruli of AAV patients, while TLR-2 and TLR-4 were scarcely detected in the glomeruli of normal controls. Double immunofluorescence staining of TLR-2, TLR-4 and CD31 indicated that TLR-4 and TLR-2 were expressed on endothelial cells in the glomeruli. In the tubulointerstitial compartment, expression of TLR-2, TLR-4 and TLR-9 could be detected in both AAV patients and normal controls. The mean optical density of TLR-2 and TLR-4 in the tubulointerstitial compartment in AAV patients were significantly higher than that in normal controls. Among AAV patients, correlation analysis showed that the mean optical density of TLR-4 in the glomeruli correlated inversely with the initial serum creatinine, the proportion of total crescents and the proportion of cellular crescents in renal specimens (r = -0·419, P = 0·041; r = -0·506, P = 0·012; r = -0·505, P = 0·012, respectively). The expression of TLR-2 and TLR-4 was dysregulated in kidneys of AAV patients. The expression of TLR-4 in glomeruli was associated with the severity of renal injury.

Undular bore theory for the Gardner equation.

We develop modulation theory for undular bores (dispersive shock waves) in the framework of the Gardner, or extended Korteweg-de Vries (KdV), equation, which is a generic mathematical model for weakly nonlinear and weakly dispersive wave propagation, when effects of higher order nonlinearity become important. Using a reduced version of the finite-gap integration method we derive the Gardner-Whitham modulation system in a Riemann invariant form and show that it can be mapped onto the well-known modulation system for the Korteweg-de Vries equation. The transformation between the two counterpart modulation systems is, however, not invertible. As a result, the study of the resolution of an initial discontinuity for the Gardner equation reveals a rich phenomenology of solutions which, along with the KdV-type simple undular bores, include nonlinear trigonometric bores, solibores, rarefaction waves, and composite solutions representing various combinations of the above structures. We construct full parametric maps of such solutions for both signs of the cubic nonlinear term in the Gardner equation. Our classification is supported by numerical simulations.

Spinal cord injury blunted effects of endothelin-1 on Ca(2+) transients and calcium current in isolated rat cardiomyocytes.

Plasma endothelin-1 (ET-1) levels are elevated in spinal cord injury (SCI), and ET-1 may be involved in the pathophysiology of this condition. However, its effects on contractile function of the heart of SCI rats are still unknown. To define more clearly the possible role of ET-1 following SCI, we investigated the effect of ET-1 on the contraction, calcium transients and L-type calcium current (I(Ca,L)) in the cardiomyocytes of control and SCI rats. Sixteen Sprague-Dawley male rats aged 80-100 days and weighing 250-350 g were randomized into control and SCI groups. Fourteen days following compression injury to the spinal cord, effects of ET-1 on the contraction, calcium transients and I(Ca,L) were studied in the cardiomyocytes of control and SCI rats by the technique of simultaneous measurement of intracellular Ca(2+) and contraction and by whole-cell configuration of the patch-clamp technique. In myocytes from control rats, ET-1 significantly increased contraction, the magnitude of Ca(2+) transients and the peak amplitude of I(Ca,L). However, ET-1 had little effect on the amplitude of contraction, calcium transients and I(Ca,L). in myocytes from SCI rats. These results suggest that the positive inotropic effects of ET-1 on control myocardial contraction may be altered in pathological states such as SCI.

[Computerized surgical simulation with 3D reconstruction of upper limbs].

This paper reports our study on how to realize computerized surgical simulation through reconstructing 3D anatomy of upper limbs. CT images and serial sections of upper limbs were matched to reconstruct 3D images. We compiled the computer programs of 3D reconstruction and surgical simulation with borland C++ computer language, and built 3D digital model of anatomic structure of upper limbs. The results showed that all structures reconstructed could be displayed alone, in any group or totally. While operating, we could choose one of three segments of the upper limbs model and operate on any parts and in any direction. The surgical simulation system could be used to design operative schemes, choose the best operative paths, and teach the processes of operations and anatomy. It could run in 586-personal computers.

[Distal clavicular fracture and dislocation of acromino-clavicular jiont treated with biopoly ligament].

OBJECTIVE: To probe into distal clavicular fracture and acromino-clavicular joint dislocation treatment. METHODS: 11 cases of distal clavicular fracture and 20 cases of acromino-clavicular joint dislocation were treated with biopoly ligament in recent 2 years. The follow-up period lasted from 3 to 24 months with an average of 16.7 months. RESULTS: Of 29 follow-up cases, 21 were excellent and 8 satisfactory. There was no redisplacement or refracture. CONCLUSION: Biopoly ligament is believed to be a good and safe material for this fracture or dislocation. This method is simple without needing a second operation for removal of implant.

[Experimental study of the effect on growth of Schwann cell from chitin and chitosan in vitro].

In order to study the effect of chitin and chitosan on the growth of Schwann cell (SC) of rats in vitro, the SC was isolated from sciatic nerve and brachial plexus of new-born rats. After the enzymatic and mechanical dissociation, the cell suspension was vaccinated on chitin membrane and chitosan fluid-coated glass coverslips. Then, the growth of SC was examined at 1, 3, 7 days after culture under light microscope and scanning electron microscope. The results showed that 94 percent of the cell grown from was SC and only 6% was fibroblast (FB), while that of the control SC 71% and FB 29% in population. The number of SC in chitosan suspension was more than that in chitin. Therefore, the conclusion was that the chitin and chitosan was histocompatible to SC, and chitosan suspension was superior to chitin, and both could inhibit the growth of fibroblast.

[A preliminary report on clinical application of biopoly ester ligament].

Sixty-one cases of fracture or dislocation were treated with France-made biopolyester ligament. They consisted of 18 cases of fracture of patella, 13 cases of fracture of olecranon, 8 cases of fracture of distal clavicle, 10 cases of dislocation of acromino-clavicular joint, 6 cases of separation of lower tibio-fibular joint, 3 cases of rapture of cruciate ligament and 3 cases of fracture of upper third of ulna with dislolcation of radial head. The follow-up period lasted from 3 to 12 months with an average of 7.3 months. The result showed that of the 56 follow-up cases, 49 were excellent and 7 were satisfactory. There was no redisplacement occured in this group. The Biopolyester ligament was believed to be a good and safe material for fractures or dislocations and was of good strength of extension and easy to use.

A survey of FRAXE allele sizes in three populations.

FRAXE is a fragile site located at Xq27-8, which contains polymorphic triplet GCC repeats associated with a CpG island. Similar to FRAXA, expansion of the GCC repeats results in an abnormal methylation of the CpG island and is associated with a mild mental retardation syndrome (FRAXE-MR). We surveyed the GCC repeat alleles of FRAXE from 3 populations. A total of 665 X chromosomes including 416 from a New York Euro-American sample (259 normal and 157 with FRAXA mutations), 157 from a Chinese sample (144 normal and 13 FRAXA), and 92 from a Finnish sample (56 normal and 36 FRAXA) were analyzed by polymerase chain reaction. Twenty-seven alleles, ranging from 4 to 39 GCC repeats, were observed. The modal repeat number was 16 in the New York and Finnish samples and accounted for 24% of all the chromosomes tested (162/665). The modal repeat number in the Chinese sample was 18. A founder effect for FRAXA was suggested among the Finnish FRAXA samples in that 75% had the FRAXE 16 repeat allele versus only 30% of controls. Sequencing of the FRAXE region showed no imperfections within the GCC repeat region, such as those commonly seen in FRAXA. The smaller size and limited range of repeats and the lack of imperfections suggests the molecular mechanisms underlying FRAXE triplet mutations may be different from those underlying FRAXA.

Distribution of FMR-1 and associated microsatellite alleles in a normal Chinese population.

The CGG repeat size distribution of the fragile X mental retardation gene (FMR-1) was studied in a population of normal Chinese X chromosomes along with that of two proximal microsatellite polymorphic markers: FRAXAC1 and DXS548. The most common CGG repeat allele was 29 (47.2%) with 30 being second most common (26%). This distribution was different from that seen in Caucasian controls, where the most common allele was 30 repeats. Other differences with Caucasian controls included a secondary modal peak at 36 repeats and the absence of peaks at 20 or 23 repeats. There were only two FRAXAC1 and five DXS548 alleles found in the Chinese sample. A striking linkage disequilibrium of FMR-1 alleles with FRAXAC1 alleles was observed, in that 90% of the 29 CGG repeat alleles but only 41% of the 30 CGG repeat alleles had the FRAXAC1 152 bp allele (18 AC repeats). This disequilibrium suggests that slippage between the closely spaced normal CGG repeat alleles, 29 and 30, and between 152 and 154 FRAXAC1 alleles is very rare. This study lays the groundwork for an understanding of founder chromosome effects in comparing Asian and Caucasian populations.