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Keywords: Natural convection, anisotropic porous medium, inversion of density.Abstract. The natural convection in the porous medium has attracted considerable attention with its applications in various industrial sectors, such as the agro-alimentary, the pharmaceutical and oil processing industries. The present work is about the study of the phenomenon of natural convection at 4°C on the vertical plate lining in an anisotropic porous medium in permeability. The wall of the vertical surface is subjected to a constant temperature with defined hydrodynamic conditions and thermal limits. Generalized Darcy’s law was used to establish the governing equations of the system. The control parameters governing the system are respectively the permeability ratio K*, the angle ϴ of the major axis and the inversion parameter R. The general basic equations were solved numerically using Runge-Kutta and shooting method. There was validated against previous work. The effect of these parameters on the heat transfer was highlighted. From the analysis result, it comes out the following conclusions: The convective flow is significantly affected by the anisotropic parameter; heat transfer along the vertical surface is maximum (minimum) when the main shaft having the high permeability is oriented parallel (perpendicular) to the gravitational field; the rate of heat transfer is depending on the inversion parameter R. The convective transfer rate illustrated by the local Nusselt number is symmetric with respect to R=0.45, where it reaches its smallest value. It is inversely proportional to the distribution of the thickness of boundary layer. A high convective transfer rate corresponds to a low boundary layer thickness and this inversely.

OBJECTIVE: To determine the relevance of surgery and other causative factors to the incidence of postoperative cognitive dysfunction (POCD) in patients with severe systemic disease. METHODS: This observational study included 107 noncardiac surgical patients and 26 nonsurgical control subjects, all of whom had an American Society of Anesthesiologists physical classification status of 3. Cognitive assessment was performed preoperatively and 7 days postoperatively, or with a 7-day interval for the control group. POCD was calculated as a combined Z-score. Mini Mental State Examination (MMSE) was used to exclude patients with pre-existing cognitive deficit (MMSE score ≥ 23). Surgical and other factors including duration of surgery/anaesthesia and length of stay in the intensive care unit (ICU) were recorded. RESULTS: After 7 days, POCD was found in 40/107 (37.4%) surgical patients compared with 4/26 (15.4%) nonsurgical controls. Preoperative MMSE score, duration of surgery/anaesthesia, and length of stay in the ICU and hospital were associated with POCD. Logistic regression analysis revealed that preoperative MMSE score was an independent predictor of POCD. CONCLUSION: Lower baseline MMSE score was the only independent predictor for POCD in patients with severe systemic disease.

This observational study investigated which of the three most common definitions of intraoperative hypotension (IOH), reported in a published systematic literature review, were associated best with anaesthetists' administration of antihypo-tensive medication (AHM). IOH and AHM use in anaesthetic procedures in a mixed surgical population (n= 2350) were also reviewed. The definitions were: arterial systolic blood pressure (SBP) < 100 mmHg or a fall in SBP of > 30% of the preoperative SBP baseline; arterial SBP < 80 mmHg; a fall in SBP of > 20% of the preoperative SBP. Accuracy of predicting AHM using these three definitions was 67%, 54% and 65%, respectively. Prediction by a new fourth definition, using an optimal threshold of minimal SBP falling to < 92 mmHg or by > 24% of preoperative baseline, was 68% accurate. In multivariate logistic analysis, age, volatile versus intravenous anaesthetics, medical history of arterial hypertension and all four definitions of IOH were associated with intraoperative AHM, however IOH was not associated with postoperative in-patient stay. The three original definitions correlated poorly with the anaesthetist's judgement about applying AHM. Anaesthetists make complex decisions regarding the relevance of IOH, considering various perioperative factors in addition to SBP. Age, physical status and duration and type of surgery showed better correlations with postoperative in-patient stay than IOH.

A secondary exploratory analysis of data from an observational study was used to study the influence of the opioid used for intraoperative anaesthesia on the incidence of post-operative delirium. Patients who had been admitted to the recovery room following elective general anaesthesia were divided into those who had received fentanyl or remifentanil. For unbiased patient analysis, matched pairs were built with respect to gender, age, physical status, anaesthetic type and surgery duration. In 752 patients, the overall incidence of delirium was 9.9% in the recovery room and 3.8% on the first post-operative day. Compared with the remifentanil group, the fentanyl group had a significantly higher incidence of delirium in the recovery room (12.2% versus 7.7%) and on the first post-operative day (5.8% versus 1.9%). Delirium in the recovery room and on the first post-operative day were both associated with a significantly prolonged post-operative hospital stay. The choice of intraoperative opioid influences the incidence of post-operative delirium. Remifentanil was associated with a lower incidence of post-operative delirium in the early post-operative period.

This study investigated the quality of documentation of post-operative nausea and vomiting (PONV) by comparing incidences collected by a research team with those reported routinely by nursing personnel. A total of 560 patients passing through an interdisciplinary recovery room were included in the study. The overall recorded incidence of PONV over 24 h was 30.7%, which was in agreement with the predicted value of 32% calculated using incidences from published randomized controlled trials. Out of the total number of 86 cases of PONV in the recovery room only 36 (42%) were detected by nursing staff. Similarly, out of the total number of 129 cases of PONV on the ward over 24 h, only 37 (29%) were recognized by nursing staff during routine care. In conclusion, PONV in routine clinical care is likely to be under-reported. To use PONV as a valid quality measure, patients need to be actively asked about nausea and vomiting at frequent intervals in a standardized fashion. A considerable proportion of patients experience PONV after discharge from the recovery room, so the assessment of PONV should cover at least 24 h post-operatively

Microvascular surgery has become an important method for reconstructing surgical defects resulting from trauma, tumors, or burns. The most important factor for successful free flap transfer is a well-executed anastomosis. This study was performed to review the authors' experience with a 1.9-m diode laser in microsurgery, with special attention to outcomes and performance of the technique.

Irinotecan is a topoisomerase I inhibitor widely used as an anticancer agent in the treatment of metastatic colon cancer. However, its efficacy is often limited by the development of resistance. We have isolated a colon carcinoma cell line, HCT116-SN6, which displays a 6-fold higher resistance to SN38, the active metabolite of irinotecan. In this paper, we studied the molecular mechanisms that cause resistance to SN38 in the HCT116-SN6 cell line. First, we analyzed proliferation, cell cycle distribution, apoptosis, topoisomerase I expression and activity in SN38-resistant (HCT116-SN6) and sensitive (HCT116-s cells). We showed that the SN38-induced apoptosis and the SN38-activated cell cycle checkpoints leading to G2/M cell cycle arrest were similar in both cell lines. Topoisomerase I expression and catalytic activity were also unchanged. Then, we compared mRNA expression profiles in the two cell lines using the Affymetrix Human Genome GeneChip® arrays U133A and B. Microarray analysis showed that among the genes, which were differentially expressed in HCT116-s and HCT116-SN6 cells, 27% were related to cell proliferation suggesting that proliferation might be the main target in the development of resistance to SN38. This result correlates with the phenotypic observation of a reduced growth rate in HCT116-SN6 resistant cells. Furthermore, 29% of the over-expressed genes were Interferon Stimulated Genes and we demonstrate that their over-expression is, at least partially, due to endogenous activation of the p38 MAP kinase pathway in SN38 resistant cells. In conclusion, a slower cell proliferation rate may be a major cause of acquired resistance to SN38 via a reduction of cell cycle progression through the S phase which is mandatory for the cytotoxic action of SN38. This lower growth rate could be due to the endogenous activation of p38.

Pork quality depends on various genetic and environmental factors. Despite the improvement of slaughter conditions, the PSE type is still one of the main concerns in this field. This study was conducted on nonstressed animals to evaluate the tissue characteristics of some muscles usually involved during stress compared with a reference muscle, the M. triceps brachii, which is actually not subject to stress-caused damages. Samples of M. triceps brachii, M. longissimus dorsi, M. biceps femoris, and M. semimembranosus were taken from pigs exhibiting 1 of the 3 HAL genotypes (NN, Nn, or nn) and 2 of the 3 RN genotypes (rn+rn+ or rn+RN−). Histoenzymology and immunohistochemistry were used to compare the fiber typing and capillary network in these muscles within these different stress susceptibility genotypes. In comparison with the reference muscle, M. triceps brachii, the combination of a high value of the number of type IIb fibers and a low vascular network showed a primary effect on muscles usually involved during stress. This led to the definition of a PSE index. A dramatic increase (P< 0.001) in this PSE index was systematically found in muscles usually involved in the PSE-type condition. These results show that distinctive histological characteristics were associated with the vulnerability of some muscles independently of the genotypes. Moreover, this study highlights the distinctive histological features of each genotype and is likely to suggest some interactions between them.

A 14‐year‐old male neutered cat experienced pulmonary embolism 15 days following surgical debridement of a recurrent dorsolumbar abscess. Clinical signs were dominated by respiratory distress. Pulmonary embolism was suggested from the lateral thoracic radiograph by the presence of an abruptly attenuated lobar artery and a contiguous oligaemic area in the caudal lung lobe. Pulmonary hypertension was demonstrated on Doppler echocardiography by right pulmonary artery dilation and tricuspid regurgitation raising the pulmonary arterial pressure to 56 mmHg. Chronic pulmonary hypertension, assumed from right ventricular wall hypertrophy, and hypokinesia, indicating chronic cor pulmonale, was suggestive of chronic rather than acute pulmonary embolism. Postmortem histological evidence of pulmonary arteriolar occlusion confirmed the diagnosis of pulmonary embolism.

The lacZ gene of Escherichia coli, coding for beta‐galactosidase, is a widely used reporter gene for gene expression studies in microbial and animal systems. To demonstrate that it is also a powerful reporter gene in plants, lacZ was fused to 5′ regulatory elements of several genes known to be functional in plant cells. By measuring LacZ activities in transgenic plants containing these gene constructs, we showed that the reporter is correctly monitoring the regulatory properties of the well‐characterized promoters fused to lacZ. beta‐Galactosidase was assayed directly in plant extracts when they contained high levels of LacZ or, when LacZ was expressed at low level, by separating the endogenous and LacZ activities electrophoretically and detecting the enzymes with a fluorogenic substrate. The most outstanding property of the marker is its amenability to histochemical detection. Due to its stability, LacZ can be fixed in the tissue with glutaraldehyde without loss of activity and detected with high resolution by using XGal. We could reveal expression patterns unnoticed earlier for many of the regulatory elements studied. The chlorophyll a/b binding protein gene, expressed at very high levels in green tissues, is also expressed at a low level in the vascular cylinder of the root. The Agrobacterium T‐DNA gene encoding octopine synthase is especially active in the epidermis of the root tip and the TR2′ gene was shown to be root specific in the intact plant and stimulated by wounding in the leaf tissue. The TR1′ gene, fused to nptII, shows similar characteristics suggesting co‐regulation of this tightly linked dual promoter.

The lacZ gene of Escherichia coli, coding for beta‐galactosidase, is a widely used reporter gene for gene expression studies in microbial and animal systems. To demonstrate that it is also a powerful reporter gene in plants, lacZ was fused to 5′ regulatory elements of several genes known to be functional in plant cells. By measuring LacZ activities in transgenic plants containing these gene constructs, we showed that the reporter is correctly monitoring the regulatory properties of the well‐characterized promoters fused to lacZ. beta‐Galactosidase was assayed directly in plant extracts when they contained high levels of LacZ or, when LacZ was expressed at low level, by separating the endogenous and LacZ activities electrophoretically and detecting the enzymes with a fluorogenic substrate. The most outstanding property of the marker is its amenability to histochemical detection. Due to its stability, LacZ can be fixed in the tissue with glutaraldehyde without loss of activity and detected with high resolution by using XGal. We could reveal expression patterns unnoticed earlier for many of the regulatory elements studied. The chlorophyll a/b binding protein gene, expressed at very high levels in green tissues, is also expressed at a low level in the vascular cylinder of the root. The Agrobacterium T‐DNA gene encoding octopine synthase is especially active in the epidermis of the root tip and the TR2′ gene was shown to be root specific in the intact plant and stimulated by wounding in the leaf tissue. The TR1′ gene, fused to nptII, shows similar characteristics suggesting co‐regulation of this tightly linked dual promoter.

Objective: This study was initiated to test the hypothesis that fetal hemodynamic changes observed under pulsatile flow bypass might be related to the release of endothelium-derived relaxing factor through oscillating shear stress. Methods: Normothermic bypass was instituted in utero in 21 preterm fetal lambs for a 1-hour period through the right atrium and main pulmonary artery. Ultrasonic flowmeters were positioned around the descending aorta and the umbilical artery. The circuit consisted of an oxygenator and a pump set to either continuous flow (n = 7) or pulsatile flow (n = 7) and adjusted to maintain a fetal main arterial pressure of 50 mm Hg. In seven other animals, endothelium-derived relaxing factor was blocked by a continuous infusion of N^@w-nitro-l-arginine after 30 minutes of pulsatile flow. Results: During the first 30 minutes of bypass, pump flows were significantly lower in the continuous-flow group than in the pulsatile-flow or blocked-flow groups (respectively, 612 +/- 144, 907 +/- 153 and 987 +/- 228 ml/min), with similar changes in aortic and umbilical flows. Systemic vascular resistances were significantly lower in the pulsatile-flow and blocked-flow groups than in the continuous-flow group (550 +/- 106 vs 821 +/- 212 dynes/sec/cm^-^5). However, after blockade of endothelium-derived relaxing factor, resistances increased gradually in the blocked-flow group to reach the level of that of the continuous-flow group at the end of bypass (943 +/- 77 vs 556 +/- 143 dynes/sec/cm^-^5 in the pulsatile-flow group). Conclusions: Blockade of endothelium-derived relaxing factor after 30 minutes of pulsatile flow returns fetal hemodynamics to continuous flow conditions. The specific inhibitor of endothelium-derived relaxing factor used in this experiment suggests that nitric oxide may be released by fetal endothelium during pulsatile bypass.(J Thorac Cardiovasc Surg 1997;114:738-45)

A 12‐year‐old female cat was diagnosed with a cranial vena caval thrombosis in association with a mediastinal lymphosarcoma. The cause of the cranial vena caval thrombosis was thought to be invasion of the venous wall by neoplastic lymphoid cells. Clinical signs of cranial vena caval thrombosis, such as swelling and oedema of the submandibular area, the ventral part of the neck and the forelimbs, were related to a space‐occupying mediastinal lymphosarcoma, which also induced respiratory distress and cyanosis. Non‐selective angiocardiography demonstrated the occlusion of the cranial vena cava and abnormal venous collateral vessels feeding the heart which are accepted as the venographic hallmark of clinically overt cranial vena caval syndrome. At postmortem examination, an intracaval thrombus, 5 cm in length, was seen extending from the costocervical vein to the sulcus terminalis of the right atrium.

Objective: This study investigates the role of various flow conditions on maternal hemodynamics during fetal cardiopulmonary bypass. Methods: Normothermic fetal bypass was conducted under pulsatile, or steady flow, for a 60-minute period. Fetal lamb preparations were randomly assigned to 1 of the 3 groups: steady flow (n = 7), pulsatile flow (n = 7), or pulsatile blocked flow bypass (n = 7), where fetuses were perfused with N^@w-nitro-l-arginine after the first 30 minutes of pulsatile flow to assess the potential role of endothelial autacoids. Results: Maternal oximetry and pressures remained unchanged throughout the procedure. Under fetal pulsatile flow, maternal cardiac output increased after 20 minutes of bypass and remained significantly higher than under steady flow at minute 30 (8.8 +/- 0.7 L . min^-^1 vs 5.9 +/- 0.5 L . min^-^1, P = .02). Maternal cardiac output in the pulsatile group also remained higher than in both steady and pulsatile blocked flow groups, reaching respectively 8.7 +/- 0.9 L . min^-^1 vs 5.8 +/- 0.4 L . min^-^1(P = .02)and5.9 +/- 0.3 L . min^-^1(P = .01)at minute 60. Maternal systemic vascular resistances were significantly lower under pulsatile than under steady flow after 30 minutes and until the end of bypass (respectively, 9.1 +/- 0.6 IU vs 12.7 +/- 1.1 IU, P = .02 and 8.9 +/- 0.5 IU vs 12.9 +/- 1.2 IU, P = .01). Infusion of N^@w-nitro-sc-arginine was followed by an increase in systemic vascular resistances from 9.3 +/- 0.7 IU, similar to that of the pulsatile group, to 13.5 +/- 1 IU at 60 minutes, similar to that of the steady flow group. Conclusions: Maternal hemodynamic changes observed under fetal pulsatile flow are counteracted after infusion of N^@w-nitro-l-arginine, suggesting nitric oxide release from the fetoplacental unit under pulsatile fetal flow conditions. (J Thorac Cardiovasc Surg 1998;116:432-9)

Objective: The ideal substitute for the treatment of ventricle-pulmonary artery discontinuity remains a topic of controversy, because of calcifications and degeneration of biologic substitutes leading to subsequent reoperations. Because polyurethane valves used in ventricular assist devices show a satisfactory biocompatibility, the aim of this study was to evaluate a valved conduit composed of a Dacron graft incorporating a trileaflet 25 mm polyurethane valve. Methods: The conduit was implanted between the right ventricle and the main pulmonary artery in adult sheep, with ligation of the proximal pulmonary artery. The animals received no medications. Serial hemodynamic data were collected at the time of implantation and at postoperative intervals of 6 and 12 months. Results: The peak pressure gradient across the valve increased significantly between implantation (0.17 +/- 5.6 mm Hg) and 6 months after operation (7.3 +/- 3 mm Hg, p = 0.0007) and remained stable thereafter (6.7 +/- 3 mm Hg at 12 months), whereas the cardiac output remained unchanged (4.6 +/- 0.6 L/min at implantation, 4 +/- 0.6 L/min at 6 months, and 3.9 +/- 1.1 L/min at 12 months). At the completion of the study, valve samples were processed and vapor coated with carbon for microscopic examination. There was one instance of nonadherent thrombus formation inside a cusp but no structural failures. The other valves were free of calcium deposits and no significant amounts of phosphorus could be detected by scanning electron microscopy and energy dispersive spectrometry. Conclusions: These data demonstrate the good hemodynamic performance, low thrombogenicity, and acceptable durability of the polyurethane valves implanted in the right side of the heart in a chronic sheep model. (J Thorac Cardiovasc Surg 1998;115:898-903)

Abstract: We have developed a “full wafer” process for producting Al/Al2O3/Cu superconductor-insulator-normal (SIN) tunnel junctions for use as X-ray and phonon sensors. We describe microfabrication details and present I–V data.

Tacrolimus-encapsulated hydrogels improve long-term survival of a vascularized composite allograft.

DNA vaccination consists of administering an antigen-coding nucleotide sequence. In order to improve the efficacy of DNA vaccines, electroporation is one of the most commonly used methods to enhance DNA uptake. Here, we discuss additional immunological effects of electroporation that are key aspects for inducing immunity in response to DNA vaccines.

Electrochemotherapy (ECT) is a local cancer treatment that has been used over the course of more than 2 decades for the removal of cutaneous and subcutaneous tumors. Several lines of evidence support the premise that the immune system is an important factor underlying anticancer treatment efficacy, potentially including patient responses to ECT. The concept of immunogenic cell death (ICD) arose a few years ago, stating that some cancer treatments generate danger-associated molecular patterns (DAMPs) that trigger an adaptive immune response against tumors. Hence, dying cancer cells behave as a therapeutic vaccine, eliciting a cytotoxic immune response against surviving malignant cells. In our study, we sought to evaluate the ability of ECT to generate cancer cell death encompassing the immunostimulatory characteristics of ICD. To this end, we assayed CT26 murine colon cancer cells in vitro in response to either electric pulses (EPs) application only or in combination with the anticancer drug bleomycin (that is ECT) by quantification of calreticulin (CRT) membrane externalization, as well as the liberation of adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1) protein. We show here that cell permeabilizing yet non-lethal electric pulses induce CRT exposure on the cell surface of EP-only treated cancer cells, as well as ATP release. However, the association of electric pulses along with the chemotherapeutic agent bleomycin was mandatory for HMGB1 release coincident with regimen-induced cell death. These data obtained in vitro were then substantiated by vaccination protocols performed in immunocompetent mice, showing that the injection of dying ECT-treated cells elicits an antitumor immune response that prevents the growth of a subsequent administration of viable cancer cells. We also confirmed previous results showing ECT treatment is much more efficient in immunocompetent animals than in immunodeficient ones, causing complete regressions in the former but not in the latter. This supports a central role for immunity in this beneficial outcome. In conclusion, we show that ECT not only possesses an intrinsic cytotoxic property toward cancer cells but also generates a systemic anticancer immune response via the activation of ICD. Hence, ECT may represent an interesting approach to treat solid tumors while preventing recurrence and metastasis, possibly in combination with immunostimulating agents.

Background: Tumor cells cultured in vitroare widely used to investigate the molecular biology of cancers and to evaluate responses to drugs and other agents. The full extent to which gene expression in cancer cells is modulated by extrinsic factors and by the microenvironment in which the cancer cells reside remains to be determined. Two cancer cell lines (A549 lung adenocarcinoma and U118 glioblastoma) were transplanted subcutaneously into immunodeficient mice to form tumors. Global gene-expression profiles of the tumors were determined, based on analysis of expression of human genes, and compared with expression profiles of the cell lines grown in culture. Results: A bioinformatics approach associated genes that showed changes in their expression levels with functional classes as defined by either the GO gene annotations or MeSH terms in the literature. The classes of genes expressed at higher levels in cells grown in vitroindicated increased cell division and metabolism, reflecting the more favorable environment for cell proliferation. In contrast, in vivotumor growth resulted in upregulation of a significant number of genes involved in the extracellular matrix (ECM), cell adhesion, cytokine and metalloendopeptidase activity, and neovascularization. When placed in comparable tissue environments, the U118 cells and the A549 cells expressed different sets of ECM and cell adhesion-related genes, suggesting different mechanisms of extracellular interaction at work in the different cancers. Conclusions: Studies of this type allow us to examine the specific contribution of cancer cells to gene expression patterns within an in vivotumor mixed with non-cancerous tissue.