Nonlinear modeling of crystal system transition of black phosphorus using continuum-DFT model.

In this paper, the nonlinear behavior of black phosphorus crystals is investigated in tandem with dispersion-corrected density functional theory (DFT-D) analysis under uniaxial loadings. From the identified anisotropic behavior of black phosphorus due to its morphological anisotropy, a hyperelastic anisotropic (HA) model named continuum-DFT is established to predict the nonlinear behavior of the material. In this respect, uniaxial Cauchy stresses are employed on both the DFT-D and HA models along the zig-zag and armchair directions. Simultaneously, the transition of the crystal system is recognized at about 4.5 GPa of the applied uniaxial tensile stress along the zig-zag direction on the DFT-D simulation in the nonlinear region. In order to develop the nonlinear continuum model, unknown constants are surveyed with the optimized least square technique. In this regard, the continuum model is obtained to reproduce the Cauchy stress-stretch and density of strain-stretch results of the DFT-D simulation. Consequently, the modified HA model is introduced to characterize the nonlinear behavior of black phosphorus along the zig-zag direction. More importantly, the specific transition of the crystal system is successfully predicted in the new modified continuum-DFT model. The results reveal that the multiscale continuum-DFT model is well defined to replicate the nonlinear behavior of black phosphorus along the zig-zag and armchair directions.

Fourteen years after the Shahid-Rajaei dam construction: an evaluation of morphometric and genetic differentiation between isolated up- and downstream populations of Capoeta capoeta gracilis (Pisces: Cyprinidae) in the Tajan River of Iran.

We evaluated the effects of the Shahid-Rajaei dam, 14 years after its construction, on morphometric and genetic divergence between up- and downstream populations of the Iranian fish Siah-Mahi (Capoeta capoeta gracilis). Sixty-six specimens were analyzed. There were significant differences between the 2 groups in the means of 16 morphometric characters (univariate analysis). In discriminant function analysis, the proportion of individuals classified into their original groups was 97 and 100% for up- and downstream populations, respectively. Principal component analysis of morphometric data demonstrated that the up- and downstream samples of Siah-Mahi are clearly distinct. In the genetic analysis, 6 informative primers produced 89 polymorphic bands with 95% polymorphism. In association analysis between morphological and genetic data, 63 of 89 genetic markers were significantly correlated with the 16 morphometric characters. We conclude that these are 2 morphologically and genetically distinct populations of C. c. gracilis, probably due to limited downstream dispersal and elimination of upstream migration.

Phylogenetic status of brown trout Salmo trutta populations in five rivers from the southern Caspian Sea and two inland lake basins, Iran: a morphogenetic approach.

Interrelationships, origin and phylogenetic affinities of brown trout Salmo trutta populations from the southern Caspian Sea basin, Orumieh and Namak Lake basins in Iran were analysed from complete mtDNA control region sequences, 12 microsatellite loci and morphological characters. Among 129 specimens from six populations, seven haplotypes were observed. Based on mtDNA haplotype data, the Orumieh and southern Caspian populations did not differ significantly, but the Namak basin-Karaj population presented a unique haplotype closely related to the haplotypes of the other populations (0·1% Kimura two-parameter, K2P divergence). All Iranian haplotypes clustered as a distinct group within the Danube phylogenetic grouping, with an average K2P distance of 0·41% relative to other Danubian haplotypes. The Karaj haplotype in the Namak basin was related to a haplotype (Da26) formerly identified in the Tigris basin in Turkey, to a Salmo trutta oxianus haplotype from the Aral Sea basin, and to haplotype Da1a with two mutational steps, as well as to other Iranian haplotypes with one to two mutational steps, which may indicate a centre of origin in the Caspian basin. In contrast to results of the mtDNA analysis, more pronounced differentiation was observed among the populations studied in the morphological and microsatellite DNA data, except for the two populations from the Orumieh basin, which were similar, possibly due to anthropogenic causes.

Which is access suitable for a solitary upper pole renal stone? A possible novel criterion.

AIM: The aim of the present study was to discover a new criterion for choosing subcostal or supracostal upper pole renal access before performing PCNL in upper pole renal stone cases. METHODS: Between April 2006 and July 2009 we performed 35 subcostal upper poles PCNL in solitary upper pole stone cases. The inclusion criteria were stone size >1.5 cm or stone size <1.5 cm and resistant to extracorporeal shockwave lithotripsy. The exclusion criteria were renal anomalies, uretero-pelvic junction obstruction, multiple stone (associated pelvic or a lower pole stone) and any contraindication for surgery. We determined access length as the new criterion (the distance between the point of needle entrance and lower border of stone on the skin) and access success, in all patients. Then we analyzed the relationship between these two main variables and used roc curve to find a reliable cut point of access length. RESULTS: The mean of access length was 9.72 cm (range: 6-14) and access was successful in 29 (82.8%) patients. Between measured variables, access length was the only variable that related to access success (P=0.04); furthermore, two reliable cut points (8 cm and 12 cm) for predicting access success. If access length was <8 cm or 8-12 cm or >12 cm, the access success was 100%, 83% and 50%, respectively. CONCLUSION: Access length can be used as a criterion for choosing subcostal upper pole renal PCNL and predicting its success, in the case of solitary upper pole renal stones 12 cm can serve as a critical valve for a decision.

Identification of transgenic foods using NIR spectroscopy: a review.

The utilization of chemometric methods in the quantitative and qualitative analysis of feeds, foods, medicine and so on has been accompanied with the great evolution in the progress and in the near infrared spectroscopy (NIRS). Hence, recently the application of NIR spectroscopy has extended on the context of genetics and transgenic products. The aim of this review was to investigate the application of NIR spectroscopy to identificate transgenic products and to compare it with the traditional methods. The results of copious researches showed that the application of NIRS technology was successful to distinguish transgenic foods and it has advantages such as fast, avoiding time-consuming, non-destructive and low cost in relation to the antecedent methods such as PCR and ELISA.

Chronic extrahepatic bile duct dilatation: sonographic screening in the patients with opioid addiction.

OBJECTIVE: One of the best known side effects of using opium is spasm of the sphincter of Oddi, which may increase the diameter of the extrahepatic bile ducts. Ultrasound is the first imaging modality used for evaluating the biliary system because it is commonly available and noninvasive. The principal objective of this study was to measure the common bile duct (CBD) diameter via ultrasonography in opium addicts and to evaluate the relation between the CBD diameter and the period of addiction. MATERIALS AND METHODS: This research was an analytical-cross sectional study that was done on 110 opium addicts that were admitted to a drug treatment center. The diameter of the CBD in these cases was measured by ultrasonography and the results were analyzed with other factors like age, the period of addiction and the laboratory findings. RESULTS: According to the findings, there is a significant increase in the range of the CBD diameter in comparison with normal bile ducts. Also, the mean diameter of the CBD in the different age groups showed a significant difference (p < 0.0001) and there was a significant relation between the CBD diameter and the period of addiction (p < 0.001, r = 0.74); so, with the increased length of the addiction period, the mean CBD diameter increases. CONCLUSION: Opium addiction is one of the factors that causes extrahepatic bile duct dilatation, so in these cases, if no obstructing lesion was found on ultrasound examination and the serum bilirobine and alkaline phosphatase levels are normal, then further evaluation is not needed.

Transgenic tilapia and the tilapia genome.

The tilapia fish (Oreochromis niloticus) has an important place in the aquaculture of the developing world. It is also a very useful laboratory animal, and readily lends itself to the transgenic technology. Through the use of reporter genes, a range of potential gene promoters have been tested in tilapia, both through transient and stable expression of the reporter construct. Using the transgenic technology, growth enhanced lines of tilapia have been produced. These fish have no abnormalities and offer a considerable growth advantage for future exploitation. It is however crucial that transgenic fish, to be exploited in aquaculture, be sterile, and various methods of achieving sterility are considered. These include triploidy, gene knock out of crucial hormone encoding genes via homologous recombination, and knock down of the function of the same genes via ribozyme or antisense technologies. Transgenic tilapia also offer the potential for exploitation as biofactories in the production of valuable pharmaceutical products, and this is also discussed.

Multicenter trial of one HLA-DR-matched or mismatched blood transfusion prior to cadaveric renal transplantation.

BACKGROUND: The beneficial effect of blood transfusions before cadaveric renal transplantation on allograft survival, although previously well documented, has become controversial in light of their adverse effects. Recently, it has been suggested that their clinical benefits are due to HLA-DR sharing between the blood donor and recipient. METHODS: In this prospective study, 144 naive patients were randomly assigned to receive one unit of blood matched for one-HLA-DR antigen (N = 49), or one unit of mismatched blood (N = 48), or to remain untransfused (N = 47). Graft survival and acute rejection rate were analyzed in 106 cadaveric renal allograft recipients receiving the same immunosuppressive protocol. RESULTS: Graft survival was similar in the three groups at one and five years: 91.7 and 80% in untransfused patients, 90.3 and 79.3% in patients transfused with one DR-antigen-matched unit, and 92.3 and 83.7% in patients transfused with HLA-mismatched blood. The difference in the incidence of six-month post-transplant acute rejections was not statistically significant in the three groups: 12 out of 36, 33.3% in nontransfused patients; 6 out of 31, 19.4% in patients transfused with one DR-matched blood; and 13 out of 39, 33.3% in patients transfused with mismatched blood. CONCLUSION: The results of our prospective randomized trial showed that in a population of naive patients, one transfusion mismatched or matched for one HLA-DR antigen given prior to renal transplantation had no significant effect on the incidence and severity of acute rejection, and did not influence overall long-term graft outcome. Considering the potentially deleterious adverse effects of blood transfusions, the costs, and the considerable logistical efforts required to select and type blood donors, such a procedure cannot be recommended in a routine practice for patients awaiting cadaveric kidney transplantation.

Long-term follow-up after liver transplantation for autoimmune hepatitis: evidence of recurrence of primary disease.

BACKGROUND/AIMS: After liver transplantation for autoimmune hepatitis, the long-term results and the incidence of recurrence of primary disease are unknown. METHODS: In this retrospective study we reviewed the clinical course of 25 patients transplanted for autoimmune hepatitis and followed for a mean of 5.3 years (2-8.5 years). RESULTS: The actuarial 5-year patient and graft survival rates were 91% (+/-6%) and 83% (+/-8%). The actuarial 1-year rate of acute rejection was 50% (+/-10.2%), which was comparable to that of patients transplanted for primary biliary cirrhosis and primary sclerosing cholangitis. Autoantibodies persisted in 77% of patients, at a lower titer than before liver transplantation. Ten patients were excluded from the study of autoimmune hepatitis recurrence, one because of an early postoperative death and nine because of hepatitis C virus infection acquired before or after liver transplantation. In the remaining 15 patients, who were free of hepatitis C virus infection, 5-year patient and graft survivals were 100% and 87%, respectively. Despite triple immunosuppressive therapy, three patients (20%) developed chronic hepatitis with histological and serological features of autoimmune hepatitis in the absence of any other identifiable cause. The disease was severe in two patients, leading to graft failure and asymptomatic in another, despite marked histological abnormalities. In one of these three patients, autoimmune hepatitis recurred on the second liver graft as well. CONCLUSIONS: Patients undergoing liver transplantation for autoimmune hepatitis have an excellent survival rate although severe primary disease may recur, suggesting the need for stronger post-operative immunosuppressive therapy.

How to stabilize the level of ionized calcium and citrate during plateletpheresis.

BACKGROUND AND OBJECTIVES: Citrate reactions are uncomfortable and potentially dangerous to apheresis donors. Reduction of citrate increases comfort, but may lead to platelet clumping. MATERIALS AND METHODS: We describe a protocol for stepwise reduction of the volume of ACD-A injected during plateletpheresis. This protocol has been carried out in 45 healthy donors with the Cobe 2997 (Cobe) cell separator, and in 35 with the Fenwal-CS 3000 (CS). RESULTS: Using this protocol, during the first hour of platelet collection, ionised calcium decreased on average by 18% for CS and by 18.4% for Cobe. During the second hour, Ca2+ and citrate ion concentration did not change with either Cobe or CS (about 65% of citrate ion load is eliminated). We observed mild signs of neuromuscular hyperexcitability in only 22% and 28% of donors with Cobe and CS, respectively. We also found a significant reduction of phosphate ions (p < 0.0001) at the end of the procedures. CONCLUSIONS: With this stepdown citrate reduction protocol, we obtained a significant reduction of injected citrate without the complication of platelet clumps.

[Immunoadsorption of anti-HLA antibodies on protein A-sepharose columns in hyperimmunized recipients waiting for transplantation]. / Immunoadsorption d'anticorps anti-HLA chez les receveurs hyperimmunisés en attente de transplantation sur colonnes de protéine A-sépharose.

In an attempt to reduce anti-HLA immunization in 15 patients awaiting for renal grafts and who were immunized against 65% of a panel of lymphocytes (titre 1/8 to 1/128), were given 5 to 7 sessions of immunoadsorption on protein A columns, immunosuppressor drugs (corticosteroids: 1 mg/kg/day + cyclophosphamid: 2 mg/kg/day) and intravenous polyclonal immunoglobulins. The antibody titres decreased in all patients, but this protocol did not sufficiently block resynthesis of antibodies. Among the 12 patients who were transplanted, the graft functioned correctly in 8 after a follow-up of 3 months to 3 years. Three early graft failures occurred in the group of 5 patients whose had had a positive cross-match before treatment. This treatment did not appear to increase the frequency of infectious complications immediately after transplantation.

How to deal with the hyperimmunized potential recipients.

End-stage renal disease (ESRD) patients with high levels of anti-HLA panel reactive antibodies (PRA) represent an increasing group in which sensitization, induced by pregnancies, previous transplants, and blood transfusions, considerably delay the opportunity to receive a graft. Currently, more than 50% of the 4700 patients awaiting transplantation in France are sensitized, of which 33% are defined as hyperimmunized (PRA greater than = 80%), and only 9.5% of the total number of transplants have been done in highly sensitized recipients. The magnitude of this problem, similar in Europe and North America, explains why more active strategies for managing hyperimmunized patients have been introduced during the past decade. Clearly, the simplest is finding of a well-matched organ that does not carry the HLA antigens against which the recipient has generated antibody, but that is limited by the number of shared grafts. The second is the development of a new cross-matching technique prior to transplantation. Attempts at immunoregulation of secreting B cell clones have been carried out using either hypertransfusions or injection of polyclonal Ig. Finally, removal and prevention of the resynthesis of HLA antibodies is a most attractive approach using immunoadsorption (IA) system with sepharose-bound protein-A columns. In our unit, fifteen ESRD patients with high levels of PRA were treated with IA. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering PRA levels, and was hampered by high de novo resynthesis of anti-HLA antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

[Relapse prevention in liver transplant patients treated for liver involvement due to hepatitis B virus]. / Prophylaxie des récidives chez les transplantés hépatiques pour atteinte hépatique due au virus de l'hépatite B.

Controversy surrounds the indication of liver transplantation in patients with hepatitis B virus infection. The major problem is the very high risk of infection of the graft. Some investigators have suggested that the presence of HBsAg is a contraindication to liver transplantation. Between February 1975 and December 1990, 178 HBs positive patients were transplanted at Paul Brousse Hospital in Professor H. Bismuth's Department, 137 for post hepatitis cirrhosis and 41 for fulminant hepatitis. Since April 1984 we have decided long term immunoprophylactic therapy for all patients with HBs infection. But only from August 1987 our supply of purified anti HBs immunoglobulin has been adequate to treat all our patients according to the following protocol: 10.000 IU during the peroperative phase, 10.000 IU immediately after intervention, 10.000 IU every day for the first 6 days, 10.000 IU when the anti HBs levels were under 150 IU/l. One hundred thirty-nine patients were treated by this method. 110 cleared HBs antigen from their sera and their liver were biologically and histologically free of B virus infection. 29 patients showed reappearance of HBs antigen in their sera and nearly all of them developed objective, histologically confirmed, graft lesions. These lesions are those of classical infection: acute hepatitis, active chronic hepatitis and cirrhosis. So 79% of patients were successfully treated with a follow up of 45 months to 6 months. We also studied the prognostic factors under treatment. The study shows: in the case of fulminant hepatitis, 93% success versus 77% in post hepatitis cirrhosis; in the case of Delta superinfection, 94% success versus 66% with pure B infection; in the absence of HBVDNA in the patient's sera before transplantation, 92% success versus 20% in the presence of HBVDNA. For a better understanding of the overall results, the two following parameters have to be considered: some patients relapsed after stopping their treatment, some other patients, despite repositivation of HBs antigen in their sera showed a paradoxal good evolution. These considerations enable us to obtain HBVDNA positive patients: 10% success, HBVDNA negative patients: Fulminant hepatitis: 100% success B Delta post hepatitis cirrhosis: 100% success B post hepatitis cirrhosis: 92% success.

Anti-HLA antibodies depletion on protein A-sepharose columns in hyperimmunized patients awaiting renal transplantation.

To reduce anti-HLA immunization, 15 patients waiting for a renal graft received the following treatment: 5 to 7 immunoadsorption sessions on protein A-Sepharose columns, immunosuppressive drugs (corticosteroids 1 mg/kg (bw/day+cyclophosphamide 2 mg/kg bw/day) and iv polyclonal immunoglobulins. Before this treatment, panel-reactive antibodies ranged from 65 to 100% and antibody titers varied from 1/8 to 1/128. In all patients, antibody, titers were decreased. However, antibody resynthesis was incompletely blocked by this protocol. Eight out of 12 grafted patients had a functional kidney transplant 3 months to 3 years post-grafting. There early kidney failures occurred in the subgroup of 5 patients who had had historical positive cross matches prior to treatment. This treatment did not seem to increase the frequency of infectious complications before or after grafting.

Immunoadsorption of anti-HLA antibodies for highly sensitized patients awaiting renal transplantation.

Fifteen end-stage renal disease patients with high titres of panel reactive (PRA) antibodies were treated with immunoadsorption (IA) on sepharose-bound protein A columns in order to remove anti-HLA antibodies and facilitate transplantation. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering panel reaction antibodies, and was hampered by high de novo resynthesis of anti-HLA antibodies. Patients whose pre-IA antibody titre was greater than or equal to 1:64 clearly did not benefit from the procedure, but other immunological criteria were not predictive of efficacy. Twelve patients were transplanted on the basis of a negative cross-match with current serum, historical sera being retrospectively tested. Surprisingly, seven patients received a well-matched graft with both pre- and post-IA negative cross-matching. Graft survival was 86% in this group. Conversely, in the group of five transplants which were performed in recipients having a positive historical cross-match with the donor, graft survival was only 40%. One patient died with a functional graft, and two grafts failed due to hyperacute humoral rejection. Humoral rejection in a third patient was successfully treated by a second IA course and administration of polyclonal IgG. We conclude that IA is a safe procedure for managing hyperimmunized transplant candidates. However, its efficacy remains variable, and a better definition of patients who should benefit from IA needs to be found.

[Safety of donors, quality of products, how much to reduce the quantity of citrate]. / Sécurité des donneurs, qualité des produits jusqu'où diminuer la quantité de citrate.

We examined 1,053 blood samples from 48 donors, for the effect of gradual reduction of citrate. We observed that: 1--Platelet count does not show any significant variation between 1/8 to 1/18 ratio. 2--In 13.3% of the cases, platelet clumping starts at 1/18 ratio. 3--There was no significant variation of the thrombin plasma level between 1/8 to 1/16 ratio (by measuring thrombin/ATIII complex). Our results show clearly that we can reduce the citrate ratio to 1/14 without expecting any adverse effect. Therefore we designated 1/14 as the security ratio. Parallel to this we also found that the average level +/- SD of ionized calcium is 100 +/- 10 muMol at 1/14 ratio.