ABSTRACT
Distal pancreatectomy with En-bloc celiac axis resection (DP-CAR) is a challenging procedure that has yielded certain clinical efficacy in the treatment of locally advanced pancreatic body/tail cancer, especially in patients with invasion of abdominal vessels. However, the clinical efficacy and safety of DP-CAR remain controversial. The study aimed to systematically review efficacy and safety of DP-CAR in the treatment of locally advanced pancreatic body/tail cancer. We systematically searched PubMed, EMBASE, Cochrane Library, and Web of Science databases from inception to 1 October 2020. Two studiers independently accomplished the study selection, data extraction, and quality assessment. Initially, of 1032 studies were searched, among which 11 high quality studies including 1072 patients were finally identified. The pooled results showed that DP-CAR versus Distal pancreatectomy (DP), the rate of R0 resection (RR = 0.76; 95%CI: 0.66 to 0.88; p = 0.0002) and 3-year survival (RR = 0.65; 95%CI: 0.43 to 0.98; p = 0.04) was lower, postoperative mortality (RR = 2.48; 95%CI: 1.02 to 6.03; p = 0.04) was higher, the operation time (MD = 104.67; 95%CI: 84.70 to 124.64; p < 0.001) and hospital stay (MD = 3.94, 95% CI 1.35 to 6.53; p = 0.003) were longer. There was no statistical difference between the DP-CAR and DP group in 1-year, 2-year survival rate (RR = 0.84; 95%CI: 0.57 to 1.23; p = 0.37) (RR = 0.70; 95%CI: 0.45 to 1.10; p = 0.12). In conclusion, compared with DP, DP-CAR has worse efficacy and prognosis survival and is more dangerous, but it can obtain better survival benefit and quality of life than palliative treatment. We suggest that DP-CAR can be carefully attempted for effective margin-negative resection. However, surgeons and patients need to know its potential perioperative risk.
Subject(s)
Pancreatectomy , Pancreatic Neoplasms , Celiac Artery/surgery , Humans , Pancreatic Neoplasms/surgery , Quality of Life , Retrospective StudiesABSTRACT
Calculating the electronic structure of systems involving very different length scales presents a challenge. Empirical atomistic descriptions such as pseudopotentials or tight-binding models allow one to calculate the effects of atomic placements, but the computational burden increases rapidly with the size of the system, limiting the ability to treat weakly bound extended electronic states. Here we propose a new method to connect atomistic and quasi-continuous models, thus speeding up tight-binding calculations for large systems. We divide a structure into blocks consisting of several unit cells which we diagonalize individually. We then construct a tight-binding Hamiltonian for the full structure using a truncated basis for the blocks, ignoring states having large energy eigenvalues and retaining states with energies close to the band edge energies. A numerical test using a GaAs/AlAs quantum well shows the computation time can be decreased to less than 5% of the full calculation with errors of less than 1%. We give data for the trade-offs between computing time and loss of accuracy. We also tested calculations of the density of states for a GaAs/AlAs quantum well and find a ten times speedup without much loss in accuracy.
ABSTRACT
OBJECTIVE: To investigate the drug-resistance of Acinetobacter baumannii (Ab) isolated from patients in burn ward, and study the incidence of 16S rRNA methylase genes mediated high-level aminoglycoside drug-resistance and its mechanism of transfer. METHODS: A total of 40 Ab clinical isolates were collected from burn ward in Gansu Province People's Hospital from May 2006 to Dec. 2007. The sensitivity of Ab for 20 antibiotics were determinated by K-B agar diffusion. The minimal inhibitory concentrations (MIC) of amikacin, gentamicin, tobramycin, netilmicin, isepamicin and kanamycin against Ab strains were determinated by agar dilution. Five kinds of 16S rRNA methylase genes including armA, rmtA, rmtB, rmtC, rmtD were amplified by PCR, the positive PCR-products were purified and sequenced, and the plasmid were extracted by alkaline lysis. The transferability of drug-resistance were determinated by conjugation and plasmid transformation tests. RESULTS: The drug-resistance rates of Ab against six aminoglycosides antibiotics was 72.5%, 72.5%, 70.0%, 67.5%, 70.0%, 70.0%, respectively. Twenty five strains were resistant to six aminoglycosides antibiotics (62.5%), among which 10 isolates were armA-positive (40.0%); rmtA, rmtB, rmtC and rmtD-positive isolates were not found. Ten transformants and 10 conjugates showed high-level resistance against aminoglycosides antibiotics, all of which the value of MIC > or = 256 microg/mL carried armA gene. CONCLUSIONS: The drug-resistance of Ab clinical isolates have high drug-resistance. 16S rRNA methylases gene exists in Ab and locates in plasmid chromosome.
