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The CBr4-photoirradiation in methanol generates a controlled source of HBr, which can chemoselectively deprotect commonly used hydroxyl-protecting groups in saccharides and nucleosides, such as tert-butyldimethylsilyl, isopropylidene, benzylidene and triphenyl ethers in the presence of other acid-labile functional groups. [Copyright &y& Elsevier]

A clean production technology spread model based on positive feedback was set up. The hobby mode, follow popularity mode of selection and corresponding technology market evolution performance were discussed. The theoretical ground for clean production policy was anlayzed and the positive analysis of policy was carried out. The environmental monitoring method was pointed as gaining comparative advantage for its dynamic efficiency. Each country should carry on suitable policies according to the reality to promote the generalization of clean production technology, to speed its market permeation and to establish a competitive technology path complying with the sustainable development as soon as possible. [ABSTRACT FROM AUTHOR]

CBr4-photoirradiation protocol was found to be a mild, highly efficient and selective method for deprotection of isopropylidene, benzylidene, triphenylmethyl and tert-butyldimethylsilyl protecting groups on sugar molecules. The conditions of this reaction can also be used to cleave peptides off from acid-labile resin linkers in solid-phase peptide synthesis. [Copyright &y& Elsevier]

The effects of mechanical stress on the dc and high-frequency performances of laterally diffused MOS (LDMOS) transistors with different layout structures were investigated by using the wafer bending method. A 3.1% peak cutoff frequency (fT) enhancement is achieved for the multifinger device under 0.051% biaxial tensile strain. For LDMOS with annular layout, the fT enhancement is increased to 3.7% due to the various channel directions. Our results suggest the strain technology can be adopted in LDMOS for RF applications. The transconductance and gate capacitance were also extracted to clearly demonstrate the fT variations. [ABSTRACT FROM AUTHOR]

This paper studied the effect of the liquidation risk on the human capital investment of employees. It pointed out that as the risk increases, employees will decrease the firm-specific human capital investment and increase the general human capital investment. If employees have the control rights, they will increase the firm-specific human capital investment and decrease the general human capital investment. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinicopathological characteristics and prognosis of patients with small (≤5 cm) solid pseudopapillary neoplasm of the pancreas (SPN) and those with large (>5 cm) SPNs., Methods: We retrospectively analyzed the clinical characteristics, laboratory findings, radiological features, treatment and prognosis of 148 patients with histologically confirmed SPN between August, 2006 and December, 2014 and compared the data between patients with small SPNs (≤5 cm) and those with large SPNs (>5 cm)., Results: In the large SPN group, the female-to-male ratio was significantly higher than that in small SPN group (61/8 vs 56/23, P=0.009) and the patients were significantly younger in large SPN group (28.3±12.3 vs 33.0±11.4 years, P=0.016). Small SPNs (≤5 cm) typically presented as inhomogeneous solid or cystic tumors, while large SPNs (>5 cm) often appeared as homogeneous solid and cystic tumors, but they did not show any significant difference in aggressive behaviors (P=0.288). The 5-year disease-free survival of patients with small SPNs was 100%, and the 1-, 3-, and 5-year disease-free survival of patients with large SPNs was 98.6%, 94.9%, and 89.3%, respectively (P=0.030), showing no significant differences in the overall survival between the two groups., Conclusion: Small SPNs and large SPNs have different clinical characteristics. Even with complete resection, tumors larger than 5 cm are more likely to have tumor recurrence and metastasis, and close follow-up is recommended for these patients.

Discovery of new antibiotics for combating methicillin-resistant Staphylococcus aureus (MRSA) is of vital importance in the post-antibiotic era. Here, we report four avenaciolide derivatives (1-4) isolated from Neosartorya fischeri, three of which had significant antimicrobial activity against MRSA. The morphology of avenaciolide-treated cells was protoplast-like, which indicated that cell wall biosynthesis was interrupted. Comparing the structures and minimum inhibitory concentrations of 1-4, the α,β-unsaturated carbonyl group seems to be an indispensable moiety for antimicrobial activity. Based on a structural similarity survey of other inhibitors with the same moiety, we revealed that MurA was the drug target. This conclusion was validated by (31)P NMR spectroscopy and MS/MS analysis. Although fosfomycin, which is the only clinically used MurA-targeted antibiotic, is ineffective for treating bacteria harboring the catalytically important Cys-to-Asp mutation, avenaciolides 1 and 2 inhibited not only wild-type but also fosfomycin-resistant MurA in an unprecedented way. Molecular simulation revealed that 2 competitively perturbs the formation of the tetrahedral intermediate in MurA. Our findings demonstrated that 2 is a potent inhibitor of MRSA and fosfomycin-resistant MurA, laying the foundation for the development of new scaffolds for MurA-targeted antibiotics.

Background: Post-pancreaticoduodenectomy (PD) hemorrhage (PPH) is an uncommon but serious complication. This retrospective study analyzed the risk factors, managements and outcomes of the patients with PPH., Methods: A total of 840 patients with PD between 2000 and 2010 were retrospectively analyzed. Among them, 73 patients had PPH: 19 patients had early PPH and 54 had late PPH. The assessment included the preoperative history of disease, pancreatic status and surgical techniques. Other postoperative complications were also evaluated., Results: The incidence of PPH was 8.7% (73/840). There were no independent risk factors for early PPH. Male gender (OR=4.40, P=0.02), diameter of pancreatic duct (OR=0.64, P=0.01), end-to-side invagination pancreaticojejunostomy (OR=5.65, P=0.01), pancreatic fistula (OR=2.33, P=0.04) and intra-abdominal abscess (OR=12.19, P<0.01) were the independent risk factors for late PPH. Four patients with early PPH received conservative treatment and 12 were treated surgically. As for patients with late PPH, the success rate of medical therapy was 27.8% (15/54). Initial endoscopy was operated in 12 patients (22.2%), initial angiography in 19 (35.2%), and relaparotomy in 15 (27.8%). Eventually, PPH resulted in 19 deaths. The main causes of death were multiple organ failure, hemorrhagic shock, sepsis and uncontrolled rebleeding., Conclusions: Careful and ongoing observation of hemorrhagic signs, especially within the first 24 hours after PD or within the course of pancreatic fistula or intra-abdominal abscess, is recommended for patients with PD and a prompt management is necessary. Although endoscopy and angiography are the standard procedures for the management of PPH, surgical approach is still irreplaceable. Aggressive prevention of hemorrhagic shock and re-hemorrhage is the key to treat PPH.

The unlimited self-renewal and multipotency of stem cells provide great potential for applications in tissue engineering and regenerative medicine. The differentiation of stem cells can be induced by multiple factors including physical, chemical and biological cues. The fate of stem cells can be manipulated by deliberately controlling the interaction between stem cells and their microenvironment. The purpose of this study is to investigate the change in matrix stiffness under the influence of neurogenic differentiation of human mesenchymal stem cells (hMSCs). In this study, three-dimensional (3-D) porous scaffolds were synthesized by type I collagen (Col) and hyaluronic acid (HA). The elastic modulus of the 3-D substrates was modified by adjusting the concentration of 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) as a crosslinking agent. The mechanical properties of Col-HA scaffolds were evaluated and the induction and characterization of hMSC differentiation toward neural lineages on substrates with different stiffnesses were studied. Using EDC of different concentrations for crosslinking, the stiffness of the matrices can be controlled in the range of 1-10 kPa for soft to stiff substrates, respectively. The results showed that MSCs were likely to differentiate into neuronal lineage in substrate at 1 kPa, while they transformed into glial cells in matrix at 10 kPa. The morphology and proliferation behavior of hMSCs responded to the different stiffnesses of substrates. Using this modifiable matrix, we can investigate the relationship between stem cell behavior and substrate mechanical properties in extracellular matrix-based biomimetic 3-D scaffolds. A substrate with controllable stiffness capable of inducing hMSCs specifically toward neuronal differentiation may be very useful as a tissue-engineered construct or substitute for delivering hMSCs into the brain and spinal cord., (Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Objective: To study the surgical management of solid-pseudopapillary tumor of the pancreas (SPTP) and its characteristics of outcome., Methods: Fifty-eight patients with SPTP of the pancreas admitted from January 2001 to December 2010 were retrospectively analyzed. There were 7 male and 51 female patients, with an average age of 30 years (ranging 9 to 70 years). Most patients were symptomatic before admission; the most common symptom was abdominal pain. Of the 58 patients, 21 patients underwent pancreaticoduodenectomy, 30 patients underwent distal pancreatectomy, 6 patients underwent central pancreatectomy, 1 patient underwent simple tumor enucleation, and 1 patients underwent duodenum-preserving pancreatic head resection., Results: The average length of stay in hospital was 23.8 days (ranging 12 to 64 days). Thirteen patients (22.4%) developed postoperative complications, including grade A postoperative pancreatic fistula of 8 cases, gastrointestinal tract bleeding of 1 case, pleural effusion of 2 cases, wound infection and fat liquefaction of 2 cases. Two patients underwent reoperation due to gastrointestinal tract bleeding or wound infection. There was no hospital death. Forty-four patients were followed-up for 7 to 136 months with an average of 41 months. All the 44 patients were alive, while 8 patients developed dyspepsia and 4 patients developed diabetes mellitus. There were no tumor recurrences or metastasis., Conclusions: SPTP is found primarily in young women. Excellent prognosis would be achieved with surgical resection.

Objective: To study the influence of the depth of jaundice, the duration of jaundice and preoperative biliary drainage (PBD) on postoperative complications and mortality after pancreaticoduodenectomy (PD)., Methods: A retrospective review was performed of the medical records of 1025 patients who underwent PD between June 1986 and December 2010. The patients comprised 659 men and 366 women, ranging from 4 to 81 years old with a mean age of (54 ± 12) years. The indications for PD were malignant disease in 869 patients (84.78%) and benign or borderline tumors in 156 patients (15.22%). The operative procedures performed were pylorus-preserving modification in 279 patients and conventional PD, i.e. Whipple's operation in 746 patients. Complications after PD were compared among the different groups which was classified according to the depth of obstructive jaundice, the duration of obstructive jaundice and whether undergoing preoperative biliary drain or not, and the analysis was made by variance analysis and χ(2) test respectively., Results: The depth of jaundice did not significantly affect the incidence of complications after PD except for the hemorrhage complication (χ(2) = 11.06, P = 0.03). The duration of jaundice had no much influence on the postoperative complications and mortality. PBD could not reduce the postoperative complications and mortality, however, it would increase the incidence of postoperative incision infection (χ(2) = 9.84, P = 0.01). No significant relationship was observed between the duration of PBD and the postoperative complications and mortality., Conclusions: Either the depth or duration of obstructive jaundice has no relationship with the postoperative complications and mortality after PD but the postoperative hemorrhage. Patients undergoing PD can not be benefited from PBD. Consequently, PBD should not be performed routinely, but it can be used in some serious patients with severe depth of jaundice who can not received surgery at once.

Objective: To investigate the determinants of long-term survival for ampulla of Vater carcinoma treated by pancreaticoduodenectomy., Methods: A total of 77 patients with ampulla of Vater carcinoma undergoing pancreaticoduodenectomy were reviewed. Kaplan-Meier method was used to analyze the survival rate. Independent t test was used for statistical comparison and COX regression model for multivariate analysis., Results: No patient died as a result of surgery. The overall 5-year survival was 40.7%. Univariate analysis showed that perioperative serum carcinoembryonic antigen (CEA) level (P = 0.012), tumor invasion depth (P = 0.000), UICC stage (P = 0.000) and tumor size (P = 0.001) were significant prognostic factors of ampulla of Vater carcinoma; in multivariate analysis, only the tumor size (P = 0.000) was an independent prognostic factor of ampulla of Vater carcinoma., Conclusion: Pancreaticoduodenectomy is associated with significant survival. Tumor size is the most important influencing factor of outcome after pancreaticoduodenectomy; in addition, perioperative serum CEA level, tumor invasion depth and UICC stage may also influence the survival rate, there exists a need for further follow-up studies.

The expedient synthesis of various 1,4-benzodiazepine-2,5-dione compounds, particularly those having substituents at the C3-, N1- and N4-positions is achieved. The important features in these synthetic strategies include: (i) using the coupling reaction of isatoic anhydride with alpha-amino ester for direct construction of the core structure of 1,4-benzodiazepine-2,5-dione; (ii) using potassium carbonate as the base of choice for selective alkylation at the N1-site, while using lithiated 2-ethylacetanilide as the required base to furnish the N4-alkylation; and (iii) using 2-nitrobenzoyl chloride as a synthetic equivalent of anthranilic acid to facilitate the polyethylene resin-bound liquid-phase combinatorial synthesis. The prepared 1,4-benzodiazepine-2,5-dione compounds are evaluated for endothelin receptor antagonism by a functional assay that measures the inhibitory activity against the change of intramolecular calcium ion concentration induced by endothelin-1. The preliminary results indicate that 1,4-benzodiazepine-2,5-diones bearing two flanked aryl substituents at the N1- and N4-sites show better inhibitory activity than the corresponding unalkylated and N-monoalkylated compounds. A promising candidate, 1-benzyl-7-chloro-3-isopropyl-4-(3-methoxybenzyl)-1,4-benzodiazepine-2,5-dione (17b), exhibits an IC50 value in low nM range.

Objective: To study the early and late changes in mRNA expression in macrophages in response to lipopolysaccharide (LPS) with a cDNA microarray approach using the Clontech Atlas microarray., Methods: mRNA was isolated from unstimulated control and LPS stimulated murine peritoneal macrophages at 2 hours and 24 hours poststimulation, converted to (33)P radiolabeled cDNA, and hybridized to mouse array membranes., Results: In macrophages being stimulated for 2 hours, 69 out of 1 176 genes were found to differ by over 3-fold compared with the control. Among them 44 genes were up-regulated and 25 genes were down-regulated. In macrophages stimulated for 24 hours, 11 genes were up-regulated and 26 genes were down-regulated compared with the control. Only 8 genes were identified both at 2 hours and at 24 hours poststimulation. The expressions of many genes encoding transcription factor, cytokines, cell signaling modulators and apoptosis associated proteins were found to have changed. Some genes that were not previously linked to this model, such as bric-a-brac (BTB) and cap-n-collar(CNC) homology 1(BACH1), early growth response protein 2 (EGR2), E47 interaction protein 1 (EIP1), Ngfi-A binding protein 2 (NAB2), myeloblastosis oncogene-like protein (MYBL2), neurofibromatosis 1 (NF1), ciliarry neurotropic factor (CNTF) and semaphorin 4A (Sema4A)., Conclusion: This study has allowed us to identify genes that may potentially be regulated by LPS at early and late phase in macrophages. These may contribute to better understanding of the mechanism underlying LPS or bacteria induced inflammatory and immune response following infection and trauma.

Background: Ischemia-reperfusion (IR) injury to the liver is still a critical and daunting problem in the field of hepatobiliary surgery. Ischemic preconditioning (IP) of the liver serves as an effective approach against IR injury. This study was to develop a novel procedure that could mimic IP, but might be more feasible than IP during surgery., Methods: Eighty-two SD rats were randomly divided into 5 groups. L group (n = 21): 0.4% lidocaine (10 mg/kg) was injected into the hepatoduodenal ligament 10 minutes before a 40-minute hepatic IR. IP group (n = 16): a 5-minute ischemia was followed by a 10-minute reperfusion prior to a 40-minute hepatic IR. ILR group (n = 15): after a 40-minute ischemia of the liver, 0.4% lidocaine (10 mg/kg) was injected into the hepatoduodenal ligament 10 minutes prior to a 40-minute reperfusion of the liver. IR group (n = 15): the liver of the rat was subjected to a 40-minute IR. Control group (n = 15): 0.9% sodium chloride was injected into the hepatoduodenal ligament without other treatments. The levels of plasma alanine transaminase (ALT) and aspartate transaminase (AST) were determined for each group after treatment., Results: The mean concentrations of ALT and AST were (379.80 +/- 141.69) U/L and (606.05 +/- 220.26) U/L for the L group, (334.64 +/- 141.94) U/L and (625.68 +/- 267.06) U/L for the IP group, (523.36 +/- 170.35) U/L and (765.47 +/- 238.45) U/L for the ILP group, (524.29 +/- 163.59) U/L and (764.63 +/- 246.79) U/L for the IR group, and (150.90 +/- 27.05) U/L and (298.15 +/- 47.68) U/L for the control group (standard error of the mean)., Conclusion: A significant decrease in ALT and AST levels was observed in the L and IP groups when compared to the ILR and IR groups (P < 0.05), but no significant difference in ALT and AST levels was observed in the L group when compared to the IP group (P > 0.05). These results suggest that pretreatment with lidocaine injected into the hepatoduodenal ligament prior to IR provides effective protection against subsequent IR injury to the liver. The novel approach of blocking innervation with lidocaine mimics hepatic IP, but is more convenient than IP at the time of liver surgery.

A series of beta-(trimethylsilyl)ethoxymethyl ethers were hydrolyzed to their corresponding alcohols in high yields by using a catalytic amount of CBr4 (15%) in MeOH under refluxing reaction conditions. The chemoselective deprotection between trialkylsilyl and beta-(trimethylsilyl)ethoxymethyl-protected alcohols can be achieved by using an alcohol with steric hindrance such as iPrOH. The selectivity also can be achieved in the CBr4/MeOH reaction mixture under ultrasonic reaction conditions.