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121.
122.
Tumor related pancreatic surgery has progressed significantly during recent years. Pancreatoduodenectomy (PD) with lymphadenectomy, including vascular resection, still presents the optimal surgical procedure for carcinomas in the head of pancreas. For patients with small or low-grade malignant neoplasms, as well as small pancreatic metastases located in the mid-portion of pancreas, central pancreatectomy (CP) is emerging as a safe and effective option with a low risk of developing de-novo exocrine and/or endocrine insufficiency. Total pancreatectomy (TP) is not as risky as it was years ago and can nowadays safely be performed, but its indication is limited to locally extended tumors that cannot be removed by PD or distal pancreatectomy (DP) with tumor free surgical margins. Consequently, TP has not been adopted as a routine procedure by most surgeons. On the other hand, an aggressive attitude is required in case of advanced distal pancreatic tumors, provided that safe and experienced surgery is available. Due to the development of modern instruments, laparoscopic operations became more and more successful, even in malignant pancreatic diseases. This review summarizes the recent literature on the abovementioned topics.  相似文献   
123.
MOTIVATION: The Profile Neighbor Joining (PNJ) algorithm as implemented in the software ProfDist is computationally efficient in reconstructing very large trees. Besides the huge amount of sequence data the structure is important in RNA alignment analysis and phylogenetic reconstruction. RESULTS: For this ProfDistS provides a phylogenetic workflow that uses individual RNA secondary structures in reconstructing phylogenies based on sequence-structure alignments-using PNJ with manual or iterative and automatic profile definition. Moreover, ProfDistS can deal also with protein sequences.  相似文献   
124.
Eu3+‐doped polystyrene and polyvinylidene fluoride (PVDF/Eu3+ and PS/Eu3+) nanofibers were made using electrospinning. These fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR), energy dispersive spectroscopy (EDX) and photoluminescence (PL). Spectral analysis of PVDF/Eu3+ and PS/Eu3+ nanofibers was based on their emission spectra. A bright red emission was noticed from Eu3+ that was assigned to the hypersensitive 5D0 → 7F2 transition. The enhanced intensity ratios of 5D0 → 7F2 to 5D0 → 7F1 transitions in the nanofibers indicated a more polarized chemical environment for the Eu3+ ions and greater hypersensitivity for the 5D0 → 7F2 transition, which showed the potential for application in various polymer optoelectronic devices. The Eu3+‐doped polymer (PVDF/Eu3+ and PS/Eu3+) nanofibers are suitable for the photoluminescent white light fabric design of smart textiles. This paper focuses on the potential application of smart fabrics to address challenges in human life.  相似文献   
125.
Esterification of α-terpineol with acetic anhydride or propionic acid mediated by Rhizomucor miehei lipase was subjected to a response surface study in order to optimize conditions for maximum esterification. The variables were enzyme/substrate (acid) ratio, α-terpineol concentration and incubation period using lipase from R. miehei. Between acetic anhydride and propionic acid, the former showed better yields at lower enzyme/substrate ratios than the latter. Yields predicted by the models for α-terpinyl propionate and α-terpinyl acetate formation were found to be in agreement with the experimentally determined ones. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
126.
The Persian walnut (Juglans regia L.), a diploid species native to the mountainous regions of Central Asia, is the major walnut species cultivated for nut production and is one of the most widespread tree nut species in the world. The high nutritional value of J. regia nuts is associated with a rich array of polyphenolic compounds, whose complete biosynthetic pathways are still unknown. A J. regia genome sequence was obtained from the cultivar ‘Chandler’ to discover target genes and additional unknown genes. The 667‐Mbp genome was assembled using two different methods (SOAPdenovo2 and MaSuRCA), with an N50 scaffold size of 464 955 bp (based on a genome size of 606 Mbp), 221 640 contigs and a GC content of 37%. Annotation with MAKER‐P and other genomic resources yielded 32 498 gene models. Previous studies in walnut relying on tissue‐specific methods have only identified a single polyphenol oxidase (PPO) gene (JrPPO1). Enabled by the J. regia genome sequence, a second homolog of PPO (JrPPO2) was discovered. In addition, about 130 genes in the large gallate 1‐β‐glucosyltransferase (GGT) superfamily were detected. Specifically, two genes, JrGGT1 and JrGGT2, were significantly homologous to the GGT from Quercus robur (QrGGT), which is involved in the synthesis of 1‐O‐galloyl‐β‐d ‐glucose, a precursor for the synthesis of hydrolysable tannins. The reference genome for J. regia provides meaningful insight into the complex pathways required for the synthesis of polyphenols. The walnut genome sequence provides important tools and methods to accelerate breeding and to facilitate the genetic dissection of complex traits.  相似文献   
127.
Tannins may reduce rumen degradability of protein, increase the proportion of feed protein reaching the lower digestive tract for enzymatic digestion and thereby increase the efficiency of protein utilization. The objective was to assess the effects of different types and levels of tannins on rumen in vitro gas production and its kinetics, in vitro true degradability (IVTD) and rumen degradability of protein (IVRDP), and microbial protein synthesis by incubating alfalfa (Medicago sativa L.) hay in buffered rumen fluid. Alfalfa was incubated in buffered rumen fluid with and without the addition of different levels of gallic acid (GA), quebracho tannin (QT), or tannic acid (TA). Tannins at the lower inclusion levels had minimal effects on fermentation products compared to the higher levels. Addition of QT and TA reduced ammonium-N (NH4+-N) concentration. Addition of QT at 20, 40, and 60 g/kg DM decreased NH4+-N by 2, 7, and 12% compared with control whereas addition of TA reduced NH4+-N by 5, 6, and 12% when added at 20, 40 and 60 g/kg DM, respectively. In experiment 2, addition of QT at 50, 100, and 150 g/kg DM, resulted in reduction of NH4+-N by 12, 30, and 51%, respectively, compared with the control. Addition of TA at 50, 100, and 150 g/kd DM reduced NH4+-N by 14, 26, and 47% compared with control. Inclusion of QT at 50, 100, 150 DM reduced IVRDP by 13, 30, and 36% compared with control whereas at these levels of inclusion, TA resulted in reduction of IVRDP by 14, 25, and 48%. Rate of gas production decreased (P<0.001), while asymptotic gas production increased (P<0.0001) with increasing level of GA and TA. Quebracho tannin decreased (P<0.0001) both the rate and asymptotic of gas production. Gallic acid had a positive effect on fermentation as indicated by increased gas production and total short chain fatty acids (SCFA) production. Quebracho tannin decreased 24 h gas production, IVTD, and total SCFA production. Acetate to propionate ratio increased with the addition of GA and but decreased when QT was added. Addition of tannins did not markedly increase total purines but numerical values tended to be higher in the presence of tannins compared with the control. Efficiency of microbial growth was lower in the presence of GA and unaltered by TA, but higher in the presence of QT compared with the control. The effect of tannins on rumen fermentation and protein degradation varied with type and level of tannins. In vivo studies will be conducted to validate the in vitro results.  相似文献   
128.
We investigated SIV infection and expression of adhesion molecules in the small intestine of rhesus macaques infected with pathogenic SIV (SIVmac) or nonpathogenic clone (SIV1A11). There was a wider dissemination and marked difference in tissue localization of SIVmac relative to SIV1A11. Our results also indicate that viral pathogenicity is associated with increased migration of inflammatory cells expressing VLA-α4, LFA-1α, Mac-1α, ICAM-1, and β2 integrin into the intestinal mucosa.  相似文献   
129.
Intraepithelial lymphocytes (IEL) are a critical effector component of the gut-associated lymphoid tissue (GALT) and play an important role in mucosal immunity as well as in the maintenance of the epithelial cell integrity and barrier function. The objective of this study was to determine whether simian immunodeficiency virus (SIV) infection of rhesus macaques would cause alterations in the immunophenotypic profiles of IEL and their mitogen-specific cytokine (gamma interferon [IFN-γ] and MIP-1β) responses (by flow cytometry) and virus-specific cytotoxic T-cell (CTL) activity (by the chromium release assay). Virally infected IEL were detected through the entire course of SIV infection by in situ hybridization. Severe depletion of CD4+ single-positive and CD4+CD8+ double-positive T cells occurred early in primary SIV infection, which was coincident with an increased prevalence of CD8+ T cells. This was in contrast to a gradual depletion of CD4+ T cells in peripheral blood. The CD8+ IEL were the primary producers of IFN-γ and MIP-1β and were found to retain their potential to produce both IFN-γ and MIP-1β through the entire course of SIV infection. SIV-specific CTL activity was detected in primary IEL at 1, 2, and 4 weeks post-SIV infection. These results demonstrated that IEL may be involved in generating antiviral immune responses early in SIV infection and in suppressing viral infection thereafter. Alterations in homeostasis in epithelia due to severe CD4+ T-cell depletion accompanied by changes in the cytokine and chemokine production by IEL may play a role in the enteropathogenesis of SIV infection.  相似文献   
130.
Gastrointestinal complications in human immunodeficiency virus (HIV) infection are indicative of impaired intestinal mucosal immune system. We used simian immunodeficiency virus (SIV)-infected rhesus macaques as an animal model for HIV to determine pathogenic effects of SIV on intestinal T lymphocytes. Intestinal CD4+ T-cell depletion and the potential for cytokine responses were examined during SIV infection and compared with results for lymphocytes from lymph nodes and blood. Flow cytometric analysis demonstrated severe depletion of CD4+CD8 single-positive T cells and CD4+CD8+ double-positive T cells in intestinal lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) during primary SIV infection which persisted through the entire course of SIV infection. In contrast, CD4+ T-cell depletion was gradual in peripheral lymph nodes and blood. Flow cytometric analysis of intracellular gamma interferon (IFN-γ) and interleukin-4 (IL-4) production following short-term mitogenic activation revealed that LPL retained same or higher capacity for IFN-γ production in all stages of SIV infection compared to uninfected controls, whereas peripheral blood mononuclear cells displayed a gradual decline. The CD8+ T cells were the major producers of IFN-γ. There was no detectable change in the frequency of IL-4-producing cells in both LPL and peripheral blood mononuclear cells. Thus, severe depletion of CD4+ LPL and IEL in primary SIV infection accompanied by altered cytokine responses may reflect altered T-cell homeostasis in intestinal mucosa. This could be a mechanism of SIV-associated enteropathy and viral pathogenesis. Dynamic changes in intestinal T lymphocytes were not adequately represented in peripheral lymph nodes or blood.  相似文献   
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