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The fundamentals of resist materials and chemistry, equipment, and process engineering for thin-film transistor (TFT) liquid crystal display (LCD) photolithography are reviewed with a primary focus on manufacturing technology. The effects of the materials and concentrations of (mainly TFTarray) photoresist constituents on the photosensitivity, dissolution behaviors in the developer, contrast, resolution, dark erosion, and stability against plasma etching are presented. Along with the equipment designs and functions, the process engineering to achieve the optimum resolution, better depth of field, higher throughput, and lower cost is explained and discussed. The efforts to address the great difficulty associated with capability/capacity improvement and increasing dimensions and weight of glass substrates and equipment are also reviewed, in response to the rising volume demands of larger displays. Mura issues related to the critical dimension (CD), differential CD, overlay, differential overlay, and total pitch are elucidated and the essential control factors and approaches are concisely introduced. Guided by the continuing, market-driven industry trends, we report the directions and future challenges for photolithography for TFT LCD applications. List of Abbreviations: CD, Critical Dimension; DNQ,Diazonaphthoquinone; DOF,Depth of Field; Eop, For Practical Manufacturing Processes, the Recommended Operation Dose which Enables the Complete Dissolution of a UV-Irradiated Positive Photoresist During Development; Eth, The Threshold Dose Above Which an Exposed Positive Resist Is Fully Soluble in the Developer; LCD, Liquid Crystal Display; NA, Numerical Aperture; PAC, Photoactive Compound; TFT, Thin-Film Transistor

Sixty-four compounds with diverse structures were used in evaluation of intrinsic clearance by various hepatocyte preparations from rats, dogs, monkeys, and humans. Intrinsic clearance (CL(int)) was calculated from the ratio of the initial amount of the test compound minus the amount remaining after 2 h of incubation and the corresponding area under the concentration versus time curve. The predictive potential of this in vitro model was tested by comparing the intrinsic clearance with in vivo clearance using linear regression analysis. In addition, the intrinsic clearance values obtained from three different types of hepatocytes (cryopreserved, fresh, and sandwich-cultured) from the same species were compared to determine the influence of preservation and culture conditions. It seems that intrinsic clearance determined from human cryopreserved hepatocyte (R(2) = 0.87) was the best predictor for the corresponding human in vivo clearance. Dog and rat hepatocyte clearances were also demonstrated to be reasonable predictors (R(2) ranged 0.68-0.85 in dogs and 0.65-0.72 in rats) for their corresponding in vivo clearances. Monkey hepatocyte clearance seems to be the worst predictor for the corresponding in vivo clearance (R(2) = 0.35-0.67). Comparison of intrinsic clearance generated from cryopreserved and fresh hepatocytes demonstrated a very good correlation in dog (R(2) = 0.82) followed by rat (R(2) = 0.77), and then by monkey (R(2) = 0.70). A similar correlation profile was shown between cryopreserved hepatocytes and sandwich-cultured hepatocytes. These results demonstrated the predictive potential of intrinsic clearance for rat, dog, and human in vivo clearance, but also showed some limitation of the approach for monkey.

Two orphan nuclear receptors, constitutive active (or androstane) receptor (CAR) and pregnane X receptor (PXR), are among the most important mediators of ligand-activated transcriptional induction of liver microsomal cytochrome P450 drug-metabolizing enzymes. CAR and PXR belong to the same NR1I receptor subfamily and show high sequence homology to each other. The vitamin D receptor (VDR) also belongs to the NR1I subfamily and has the second highest homology to CAR in the ligand binding domain. A 3D model of the ligand binding domain of human CAR (hCAR) was constructed based on the available X-ray structures of human PXR (hPXR) and VDR (hVDR). The model shows that the size of the ligand binding cavities of hCAR and hPXR are similar, but larger than that of hVDR. hPXR's capability of binding to extremely large ligands, such as rifampicin, implies that its binding cavity may be able to expand further through the flexibility of a surface loop. In contrast, hCAR does not have this loop so that its cavity cannot expand, suggesting that hCAR would not bind to the largest hPXR ligands. Docking calculations of selected ligands to hCAR, based on the structural model, are consistent with previously reported receptor binding data. The results from this study indicate that structural modeling will be a useful tool for understanding ligand binding to hCAR and for design of drugs free of hCAR-mediated enzyme induction.

The purpose of this article is to show that the limiting case of the Carnot vapor cycle with a temperature difference of only a few degrees between hot and cold reservoirs, can be interpreted as the idealized heat pipe (Carnot heat pipe) for transporting heat, utilizing the boiling condensation processes. The observation of the basic relationship (definition of absolute temperature) Q1/ Q2 = T1/ T2 for Carnot cycle reveals that the Carnot heat engine becomes a heat transfer device when the temperature difference is very small. The Clapeyron—Clausius equation for the infinitesimal (differential) Carnot vapour cycle becomes the genesis for the operating principle of the heat pipe and two-phase thermosyphon. The Carnot heat pipe is independent of the system and working fluid. Within the context of the idealized Carnot heat pipe, it is shown that thermodynamics, fluid mechanics and heat transfer (thermal sciences) are closely coupled in heat pipe operation. The present observation is based on various expositions of classical thermodynamics available in the historical literature. It is of interest to note that the Carnot vapor cycle provides the basic principle for heat pipe and two-phase thermosyphon in addition to the classical cases of heat engine, refrigeration machine and heat pump.

This paper explores the use of neural networks as a novel approach in the implementation of spectral library search for gas chromatography mass spectrometry which is a common and powerful analytic tool for the forensic drug chemists nowadays. A total of 28 drugs currently under control in Hong Kong were chosen for the study. Real forensic data, which represents mass spectra obtained under various conditions ranging from good to poor, were used for training and testing. Salient features from the spectral data were extracted using Simpson's diversity index, and such features were presented to various neural networks as input. A total of 355 spectra were used for training the neural networks, and a further set of 163 spectra was used for evaluation. All the neural networks performed well, with recognition rates above 97.5%. Moreover, the best performing neural network achieved perfect recognition.

Instability, laminar - turbulent transition, and laminarization phenomena for slightly heated air flow in a curved square duct are studied by temperature fluctuation measurements for Reynolds numbers in the range Re=10 3 - 104. The method is based on the analogy between fluctuating temperature field and the fluctuating velocity component in the streamwise direction for forced convection. The fast Fourier transform (FFT) and the power spectrum density reveal the frequency and amplitude characteristics of the flow transition. The possibility of studying turbulence phenomena using passive scalar transport in developing turbulent flow is demonstrated. The stabilizing effects of centrifugal forces exist near the inner wall and the destabilizing effects dominate in the region near the outer wall. For flow near the outer region, the temperature turbulence intensity increases to a peak value and then decreases to a fully developed value for turbulence with the increase of Reynolds number. At Re=104, turbulent flo...

Experimental allergic encephalomyelitis is an animal model of a T cell-mediated autoimmune disease -- for example, multiple sclerosis. We demonstrated that mice with experimental allergic encephalomyelitis developed retrocochlear hearing loss, and that the lesion of the auditory pathway might be related to T cell receptor Vbeta8-expressing T cells. To investigate whether anti-Vbeta8 antibody could prevent hearing loss, we carried out brain stem auditory evoked potential testing, histologic examinations, and flow cytometry in antibody-treated and control myelin basic protein-immunized B10.PL mice. The antibody was administered just before immunization of myelin basic protein. The disease incidence and severity were significantly reduced in the mice injected with the antibody. The results of brain stem auditory evoked potential testing, histologic examinations, and flow cytometry indicated that the depletion of Vbeta8-expressing T cells brings the prevention of hearing loss, as well as prevention of other neurologic deficits. The development of T cell receptor-specific antibody therapy might help treat retrocochlear hearing loss in multiple sclerosis.

Flow visualization results for secondary flow phenomena at the exit of 90° and 180° bends and helically coiled pipes (1, 2 and 5 turns), (radius of curvature R_c = 381 mm, inside pipe diameter d=37.5 mm, curvature ratio d/2R_c = 0.049) and in the downstream straight pipe ( l/d = 30 ) are presented to study the stabilizing (relaminarization) effect in curved pipes with fully developed entry turbulent air flow and the destabilizing (re-transition from laminar to turbulent flow) effect in the downstream straight region. The entry Reynolds numbers are Re = 2200, 3200, 4300 and 5300). The related measurement results using a hot-film anemometer are presented for developing profiles of the time-mean streamwise velocity distribution and the axial turbulence intensity field in the 180° return bend and in the downstream straight pipe for Reynolds numbers Re = 3200, 4300, 6300 and 8200. The time traces showing the output of the hot-film sensor are also presented for developing fluctuating velocity field in the 180° bend and in the downstream straight pipe for the same Reynolds number range. Some aspects of the relaminarization phenomena in curved pipes and the re-transition phenomena from laminar to turbulent flow in the downstream straight pipe are clarified by the present experimental investigation.

An attempt is made to provide historical perspectives on the influences of Newton's law of cooling (1701) on the development of heat transfer theory. Newton's cooling law provides the first heat transfer formulation and is the formal basis of convective heat transfer. The cooling law was incorporated by Fourier (1822) as the convective boundary condition (Biot number) in his mathematical theory of heat conduction. The decisive step in the application of the concept of heat transfer coefficient occurred with the publication of the “basic law of heat transfer” by Nusselt in 1915. Newton's law is valid only for forced convection with constant physical properties. The close relationships for various heat transfer theories are pointed out. Heat transfer phenomena can also be classified based on the relationship between surface heat flux and temperature difference as a driving force.

Flows in channels with streamwise curvature and spanwise rotation are visualized in terms of end-view near the exit of the test sections through injecting smoke into the flows. Two test sections are used, i.e. the rectangular channels with the aspect ratio of and 10, respectively. The work focuses on visualization of Dean and Coriolis vortices under the effects of secondary instabilities and flows in the region with a relatively high rotation speed. The results show that the secondary instabilities cause the Dean and Coriolis vortices oscillating in various forms and the flows at high rotation speeds are controlled by the secondary instabilities rather than the primary instability. In particular, the secondary instabilities lead the flows to be unsteady and turbulent somewhat like the bursting flow in the turbulent boundary layers.

OBJECTIVE To investigate whether or not there is an increased risk of pulmonary tuberculosis (PTB) after non-tuberculous mycobacterial (NTM) disease. DESIGN A retrospective cohort study of 212 NTM patients and 4240 control cases. RESULTS Patients with previous NTM disease had a significantly higher incidence of PTB than controls (incidence rate ratio [IRR] 14.74, 95%CI 8.71-24.94, P < 0.0001). Cox's proportional hazards analysis yielded an adjusted hazards ratio (aHR) of 10.15 (95%CI 5.67-18.17, P < 0.05) for NTM-associated PTB. The majority of the PTB cases (17/23, 73.9%) were diagnosed within 6 months after the diagnosis of NTM disease. Older age (≥65 years, aHR 4.45, 95%CI 1.94-10.22, P < 0.05), male sex (aHR 1.75, 95%CI 1.01-3.13, P < 0.05), human immunodeficiency virus (HIV) infection (aHR 12.49, 95%CI 3.20-48.79, P < 0.05) and chronic obstructive pulmonary disease (aHR 4.46, 95%CI 2.19-9.10, P < 0.05) were independent risk factors for developing PTB after NTM disease. The cumulative incidence of PTB in patients with previous NTM disease was significantly higher than in controls (P < 0.0001, Kaplan-Meier analysis). However, there was no significant difference in the survival rates in the two cohorts. CONCLUSION Increased PTB prevalence after NTM disease was demonstrated. HIV infection was the greatest independent risk factor for subsequent development of PTB.

The simultaneous effects of curvature, rotation and heating/cooling of the tube complicate the flow and heat transfer characteristics beyond those observed in the tubes with simple curvature, rotation or heating/cooling. The phenomena encountered are investigated for steady, hydrodynamically and thermally fully developed laminar flow in circular tubes. A full second-order perturbation solution is obtained under the condition that the wall heat flux is uniform with peripherally uniform wall temperature. The results cover both the nature of flow transitions and the effect of these transitions on temperature distribution, friction factor and Nusselt number. When the rotation is in the same direction as the main flow imposed by a pressure gradient and the fluid is heated, the flow and heat transfer remain similar to those observed in stationary curved tubes, radially rotating straight tubes or mixed convection in stationary straight tubes. There are, however, quantitative changes due to the combined effects of centrifugal, Coriolis and buoyancy forces. A more complex behaviour is possible when the rotation is opposite to the flow due to the pressure gradient or when the fluid is cooled. In particular, the inward Coriolis force and/or buoyancy force may cause the direction of the secondary flow to reverse. The flow reversal occurs by passing through a four-cell vortex flow region where overall, the centrifugal, Coriolis and buoyancy forces just neutralize each other.

The possibility of using a fine thermocouple to detect the onset of unsteady motion in slightly heated gases is explored. Signals from thermocouple measurements using Chromel-Constantan thermocoupl...

Rapid DNA analysis based on allele-specific polymerase chain reaction (PCR) using mutation site-specific primers was developed to detect mutations in the CYP21 gene known to cause steroid 21-hydroxylase deficiency. In contrast to the previous method, in which PCR of genomic DNA was followed by dot blot analysis with radioactive probes and multiple rounds of stripping and reprobing for each of the 8 most common mutation sites, the results using this new method were immediately visualized after the PCR run by ethidium bromide-stained agarose gel electrophoresis. Using allele-specific PCR, mutation(s) were identified on 148 affected chromosomes out of 160 tested. Although mutation(s) were identified on only one chromosome of 11 of these patients, their parents showed a consistent pattern on DNA analysis. The only exception was that in one family, in which the parents each had a detectable mutation, a mutation was detected on only one allele of the patient. Most likely there is a mutation in the patient's other allele that could have arisen de novo or was inherited from the parent and was not evident in the transmitting parent's phenotype. When compared with the dot blot procedure, allele-specific PCR is more rapid, less labor-intensive, and avoids the use of radioactivity.

Experiments on visualization of stabilizing and destabilizing flow in channels with curvature and rotation are described. Two test sections have been used, i.e., the rectangular channels with aspect ratios of 1 and 10, respectively. The results show the end view of flows in the region with a low negative rotation speed. In addition, a generalized Rayleigh criterion is formulated about the primary instability of flows in rotating curved channels to help in understanding the experimental results.

The interstitial chromosome (chr.) 1q21-q22 region is frequently amplified in human cancers, where it has been reported to carry prognostic significance for patients. We attempted to delineate chr. 1q21-q22 for affected gene(s) in hepatocellular carcinoma (HCC) by array-CGH and detected copy number gains of ρ-guanine nucleotide exchange factor-H1 (GEF-H1) as most significant event. Gene expression evaluation in the HCC cohort indicated common up-regulations of GEF-H1 in 64% tumours compared to adjacent non-tumoural liver (64/100; paired t-test p0.0001). Moreover, GEF-H1 over-expressions correlated with microvascular invasion and advanced-stage tumours (p0.05). High GEF-H1 levels also predict shorter disease-free and overall survival of HCC patients (p0.03). Functional knock-down of GEF-H1 by RNAi indicated marked reduction in cell invasion through matrigel and an inhibition of cell migration (p0.035), but an effect on cell viability was not apparent. More interestingly, a mesenchymal-epithelial transition (MET) was readily observed in GEF-H1 knock-down cells, where a concomitant re-expression of epithelial markers (E-cadherin and cytokeratin 18) and cell adhesion proteins (α-catenin and γ-catenin) was found but down-regulation of mesenchymal features (N-cadherin, vimentin and fibronectin). This phenotype was accompanied by reduced filamentous actin polymerizations and diminution of the stress fibre formation. In addition, reduced active form of GTP-RhoA, together with its downstream effectors, including cleaved ROCK1 and phosphorylated MLC2, were also detected in GEF-H1-depleted cells. Taken together, our findings underscore a potent oncogenic role for GEF-H1 in promoting the metastatic potentials of HCC, possibly through activation of RhoA signalling and the EMT phenomenon.

Starting from indole-based C-3 pyridone HCV NS5B polymerase inhibitor 2, structure-activity relationship (SAR) investigations of the indole N-1 benzyl moiety were performed. This study led to the discovery of irreversible inhibitors with p-fluoro-sulfone- or p-fluoro-nitro-substituted N-1 benzyl groups which achieved breakthrough replicon assay potency (EC(50) = 1 nM). The formation of a covalent bond with adjacent cysteine-366 thiol was was proved by mass spectroscopy and X-ray crystal structure studies. The C-5 ethyl C-2 carboxylic acid derivative 47 had an excellent oral area-under-the-curve (AUC) of 18 μM·h (10 mg/kg). Its oral exposure in monkeys and dogs was also very good. The NMR ALARM assay, mass spectroscopy experiments, in vitro counter screening, and toxicology assays demonstrated that the covalent bond formation between compound 47 and the protein was highly selective and specific. The overall excellent profile of 47 made it an interesting candidate for further investigation.

The developing secondary flow patterns caused by buoyancy forces in the simultaneous hydrodynamic and thermal entrance region of a horizontal rectangular channel (aspect ratio, a/b = 2) with isothermally heated lower wall and/or isothermally cooled upper wall are studied using the smoke injection method. The entrance air is at room temperature (around 23°C), and the temperature ranges for the lower and upper walls are 23-51°C and 15-23°C, respectively. The mean air velocities are 0.1, 0.2, 0.3, and 0.4 m/s. The Reynolds number varies from Re = 2.10 × 10 2 to 1.05 × 10 3 and the Grashof number ranges from Gr = 1.56 × 10 5 to 5.04 × 10 5 . Photographic results reveal mixed convection, convective instability, and chaotic phenomena. Many new secondary flow patterns are revealed by this flow visualization study, and the photographic results should be useful for future theoretical study and measurements. The experiments were designed to understand flow physics

Starting with the indole-based C-3 pyridone lead HCV polymerase inhibitor 2, extensive SAR studies were performed at different positions of the indole core. The best C-5 groups were found to be compact and nonpolar moieties and that the C-6 attachments were not affecting potency. Limited N-1 benzyl-type substituent studies indicated that the best substitutions were fluoro or methyl groups at 2' or 5' positions of the benzyl group. To improve pharmacokinetic (PK) properties, acylsulfonamides were incorporated as acid isosteres at the C-2 position. Further optimization of the combination at N-1, C-2, C-5, and C-6 resulted in the identification of compound 56, which had an excellent potency in both NS5B enzyme (IC(50) = 0.008 μM) and cell-based replicon (EC(50) = 0.02 μM) assays and a good oral PK profile with area-under-the curve (AUC) of 14 and 8 μM·h in rats and dogs, respectively. X-ray structure of inhibitor 56 bound to the enzyme was also reported.

This paper presents a real-time image processing of human face identification for home service robot (HSR). This vision system is set up by two individual sub-systems. The first one is face detection and tracking sub-system based on adaptive skin detector, condensation filter with parallel computing particles, and Haar-like classifier. And a simple and fast motion predictor is also proposed for face tracking. The second is face recognition system based on embedded HMM (EHMM) with parallel training and recognition procedures. In order to reach a fast, robust, efficient, this study used extensible parallel integrated vision system (PIVS). Finally, real-time experimental results on different humans in different unknown scenes demonstrate that the proposed PIVS is indeed feasible, simple and safe.

Objectives Hepatitis C virus (HCV) infection represents a major worldwide-health problem. The current standard of care is combination therapy with pegylated interferon and ribavirin, which achieves a successful response in only approximately 40% of genotype I patients. Key findings The biology of HCV infection has been under intensive research and important progress has been made in understanding the replication cycle of the virus. Several therapeutic targets have been under investigation, such as NS3 protease, NS4A replicase and NS5B polymerase. New potential targets, such as NS2 protease, as well as CD-81 and claudin-1 entry co-receptors, have also been identified. Summary Clinical evaluations of drug candidates targeting NS3 protease, NS4A cofactor, and NS5B polymerase have demonstrated the potential of developing small molecules that interfere with the replication of the virus. Additional issues, including genotype coverage, resistant mutations, and combination therapy represent major challenges for future drug discovery efforts.

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics.Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics. Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Open anatomical liver resections remain one of the most effective treatments of hepatocellular carcinoma (HCC) and results in better recurrence-free and overall survival compared to nonanatomical resections [1]. On the other hand, laparoscopic hepatectomies for HCC have recently emerged with the benefits of reduced blood loss, shorter hospital stay, and less severe wound pain [2, 3]. Classically, liver lesions considered suitable for laparoscopic resection were those small tumors (4 cm) located over the anterior and left lateral segments [3]. However, we would like to expand the current indications and here we present our techniques of laparoscopic anatomical resection for a HCC that was located at right posteriosuperior segment 7.Our patient was a 60-year-old gentleman who had Child's A hepatitis B cirrhosis and was on entecavir. During a follow-up CT scan, a 2.6-cm segment 7 lesion with early arterial enhancement and contrast washout was noted and was subsequently confirmed with arteriogram. α-Fetoprotein was 3 ng/ml (normal20 ng/ml). The video demonstrates a posterior approach to laparoscopic resection of segment 7.Operative time was 510 min. Blood loss was 800 ml and no perioperative transfusion was required. Postoperative recovery was uneventful and only simple oral analgesics were required for pain control. He was discharged on postoperative day 6. Histology showed a moderately differentiated hepatocellular carcinoma and all resection margins were clear. Subsequent follow-up CT scan 6 months after the operation showed no evidence of recurrence and α-fetoprotein level was normal.Laparoscopic hepatectomy for HCC over the right posterior segment of the liver is feasible in selected patients with favorable results in terms of wound size, postoperative recovery, and hospital stay. Maximal liver conservation was achieved in performing oncologic anatomical resection of segment 7 instead of a posterior sectionectomy. On the other hand, a posterior approach was recommended because it allowed early intrahepatic control of pedicles and identification of the right hepatic vein to guide parenchymal transection along the intersegmental plane.

The use of intrinsic metabolic stability/clearance and other in vitro pharmacokinetic data for the selection of drug candidates for clinical evaluation during discovery lead optimization has become one of the primary focuses of research organizations involved in new drug discovery. Using intrinsic clearance determined from human liver microsomal preparations and/or hepatocyte to predict human clearance has become more acceptable.This review focuses on the current methods for determining intrinsic clearance and scaling to predict human hepatic clearance, and novel physiologically-based models for improvement of human hepatic clearance prediction. Published microsomal metabolic stability data and in-house hepatocyte clearance data were compared with published in vivo human hepatic clearance data. Various scaling models and the effect of protein binding were examined.Use of a novel microfluidic model and other physiologically-based models are presented. Microsomal metabolic clearance requires correction for protein binding and in vitro microsomal binding in order to better predict in vivo hepatic clearance of compounds that are mainly eliminated by hepatic metabolism.Metabolic clearance obtained using hepatocytes may work well in combination with the well-stirred model. Novel models incorporating flow and protein binding in the system may be the most complete models for prediction of human in vivo metabolism.

This article traces the historical development of the basic concepts in thermodynamics from the time of Galileo (1592) to the time of Planck (1900) to gain historical perspectives. The review of the theory of heat as a branch in physics and thermodynamics is based on secondary sources. Some observations are made regarding the analogous physical phenomena in conduction and convection heat transfer problems. It is pointed out that Newton's cooling problem (1701) is closely related to Graetz's thermal entrance region problem (1885), and Prandtl's boundary-layer concept (1904) can be traced to transient heat conduction problems involving semiinfinite solids. It is also noted that the heat pipe (1964) represents a limiting case of the Carnot cycle (1824) with zero power output.

Homozygous deletion screening has been widely utilized to define tumour suppressor genes (TSGs) in cancers. Although these biallelic deletions are infrequent, their identification has facilitated the discovery of many important TSGs. We have systematically examined the genome of hepatocellular carcinoma (HCC), a highly malignant tumour that is rapidly fatal, for the presence of homozygous deletions. Array-CGH analysis on early passage of HCC cultures and cell lines led us to identify six homozygous deleted (HD) regions. A high concordance between array-CGH and expression of HD genes was demonstrated, where crystallin Lambda1 (CRYL1; located on chromosome 13q12.11) displayed the most frequent down-regulation. We found that reduced mRNA expression of CRYL1 was common in HCC tumours when compared with their adjacent non-tumoural liver (p = 0.0097). Significant associations could also be drawn between repressed CRYL1 and advanced tumour staging, increased tumour size, and shorter disease-free survival of patients (p0.037). Moreover, homozygous deletions on CRYL1 could be detected in 36% of HCC cases, where recurrent HDs were identified on exons 1, 5, and 8. Examination of other causal events suggested histone deacetylation and promoter hypermethylation to be likely inactivating mechanisms as well. Re-expression of CRYL1 in the SK-Hep1 cell line, where biallelic loss of CRYL1 was found, induced profound inhibition of cellular proliferation and cell growth (p0.0015). By Annexin V staining, CRYL1 restoration readily increased pro-apoptotic cells with an induction of PARP cleavage. Flow cytometry further revealed that CRYL1 could prolong the G(2)-M phase, possibly through interruption of the Cdc2/cyclin B pathway. Given that regional chromosome 13q12-q14 loss is a causal genomic event in HCC tumourigenesis, our finding may have implications for identifying a novel TSG CRYL1 within this important locus.

In the search for a second generation HCV protease inhibitor, molecular modeling studies of the X-ray crystal structure of Boceprevir® 1 bound to the NS3 protein suggest that expansion into the S4 pocket could provide additional hydrophobic Van der Waals interactions. Effective replacement of the P4 tert -butyl with a cyclohexylmethyl ligand led to inhibitor 2 with improved enzyme and replicon activities. Subsequent modeling and SAR studies led to the pyridine 38 and sulfone analogues 52 and 53 with vastly improved PK parameters in monkeys, forming a new foundation for further exploration.

Hepatitis C (HCV) infection is a global health crisis leading to chronic liver disease. In our efforts towards a second generation HCV NS3 serine protease inhibitor with improved profile, we have undertaken SAR studies in various regions of Boceprevir including P2. Herein, we report the synthesis and structure–activity relationship studies of inhibitors with ( S )-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxylic acid 2 as P2 substituent replacing the (1 R ,2 S ,5 S )-6,6-dimethyl 3-azabicyclo[3.1.0]hexane-2-carboxylic acid. The systematic investigation led to the discovery of highly potent inhibitor 25 ( K i ∗ = 7 nM, EC 90 = 30 nM) with improved rat exposure of 2.56 μM h.

SAR studies on the extension of P3 unit of Boceprevir (1, SCH 503034) with amides and lactams and their synthesis is described. Extensive SAR studies resulted in the identification of 36 bearing 4, 4-dimethyl lactam as the new P4 cap unit with improved potency ( K i ∗ = 15 nM , EC 90 = 70 nM) and pharmacokinetic properties (Rat AUC (PO) = 3.52 μM h) compared to 1.

Within the global pharmaceutical and biotech industries, there is significant interest in identifying in vitro screening systems that are more human-relevant-i.e., that offer greater utility in predicting subcellular and cellular physiological responses in humans in vivo-and that thereby allow investigators to reduce the incidence of costly late-stage failures during pharmaceutical clinical trials, as well as to reduce the use of animals in drug testing. Currently incumbent in vitro screening methods, such as culturing human hepatocytes in suspension, while useful, are limited by a lack of long term cellular function. In order to address this limitation, we have established an integrated, microfluidic, in vitro platform that combines the patented HmuREL((R)) microdevice with a hepatic coculture system. In the present report, we use this platform to study clearance and metabolite generation of a battery of molecular entities. The results show that the flow-based coculture system is capable of clearing, with improved resolution and predictive value, compounds with high, medium, and low clearance values. In addition, when coculture is coupled with flow, higher metabolite production rates are obtained than in static systems.

S5, a hepatitis C virus protease inhibitor, displays partially saturable efflux in the Caco-2 system. In addition, the efflux can be reversed by cyclosporine, indicating that S5 may be a human P-glycoprotein (P-gp) substrate. S5 can also activate the ATPase activity in vesicle membranes containing mouse P-gp 1a and 1b, suggesting that S5 may be a substrate for mouse P-gp. The pharmacokinetics and tissue distribution of S5 were evaluated after intravenous and oral administration to wild-type and 1a/1b knockout mice. Plasma and kidney levels of this compound in knockout mice were transiently higher than those in wild-type mice only after oral dosing, indicating effective P-gp efflux occurs in wild-type mice. The levels of S5 in brain samples from knockout mice were higher than those from wild-type mice after both intravenous and oral administration, but much more significantly after intravenous administration. The levels in liver were four time higher in knockout mice than in wild-type mice after oral administration, but were not different between knockout and wild-type mice after intravenous administration. These results suggest that P-gp efflux limits exposure to S5 in the brain and liver, and that the effect is dependent on the route of administration.

The exact mathematical analogy exists between Newton’s law of cooling and Proposition II, Book II (The motion of bodies in resisting mediums) of the Principia. Several approaches for the proof of Proposition II are presented based on the expositions available in the historical literature. The relationships among Napier’s logarithms (1614), Euclid’s geometric progression (300 B.C.), and Newton’s law of cooling (1701) are explored. Newton’s legacy in the thermofluid sciences is discussed in the light of current knowledge. His characteristic parameter for the temperature fall ratio, ΔT/(T−T∞), is noted. The relationships and connections among Newton’s cooling law (1701), Fourier’s heat conduction theory (1822), and Carnot’s theorem (1824)based on temperature difference (ΔT) as a driving force are noted. After tracing the historical origins of Newton’s law of cooling, this article discusses some aspects of the historical development of the heat transfer subject from Newton to the time of Nusselt and Prandtl. Newton’s legacy in heat transfer remains in the form of the concept of heat transfer coefficient for conduction, convection, and radiation problems. One may conclude that Newton was apparently aware of the analogy of his cooling law to the low Reynolds number motion of a body in a viscous fluid otherwise at rest, i.e., its drag is approximately proportional to its velocity.

The rising costs and time associated with bringing new medicines to the market have created a need for a new paradigm for reducing the attrition rates of drug candidates in both preclinical and clinical development stages. Early appraisal of drug metabolism and pharmacokinetic (DMPK) parameters is now possible due to several higher throughput in vitro and in vivo screens. This knowledge of DMPK properties should not only shorten the timelines for the selection of drug candidates but also enhance the probability of their success for development. The role of DMPK researchers in the drug research paradigm should not be limited to screening a large array of compounds during the lead optimization process but should include a strive for an understanding of the absorption, distribution, metabolism, excretion, and potential drug-related toxicities of a chemical series. As an example, in this article we present a specific DMPK research screening paradigm and describe a case study using the Thrombin Receptor Antagonist program. This screening paradigm followed by the extensive lead optimization process culminated in the selection of SCH 530348, a potent, selective and orally active thrombin receptor antagonist for the treatment of thrombosis.

Cytochromes P-450 2C11 and 2C13 are the major CYPs in rat liver microsomes. Despite a high degree of sequence identity, these two isozymes display different positional and regio-specific metabolism of steroid hormones, such as testosterone. CYP2C11 converts testosterone to 2α-hydroxyl and 16α-hydroxyl metabolites, while CYP2C13 produces primarily the 6β-hydroxyl metabolite. Using a human CYP2C9 crystal structure as the template, homology models were generated for CYP2C11 and CYP2C13. Despite similar volume of the binding pockets for CYP2C11 and CYP2C13, the models for these two CYPs showed a substantial difference in the shape of the substrate-binding sites. Substrate docking using rigid and induced-fit methods showed that testosterone fits into the substrate-binding sites of both CYP2C11 and CYP2C13 without the need of added constraints. These docking exercises appear to support testosterone binding in both CYP2C11 and CYP2C13. A constrained docking using energy minimization is required to position testosterone for more precise positional and regio-specificity in supporting the observed metabolism. These results demonstrate the complexity of using modeling for understanding the binding of substrate to CYPs, and suggest that, as a complement to the metabolism data, modeling and docking may yield reliable structural information for the molecular interaction between the substrate and the CYPs.

The discovery of 1 as a high-affinity ligand for the nociceptin receptor has led to the synthesis of a series of tropane (8-methyl-8-azabicyclo[3.2.1]octane) derivatives as optimized ligands. These compounds exhibit high affinity for the nociceptin receptor, moderate to excellent selectivity over the opioid μ receptor, and behave as full agonists. In this Letter, we present the synthesis and highlight the structure–activity relationship of tropane derivatives culminating in the identification of 24 and 32 as potent and orally active antitussive and anxiolytic agents. The in vitro and in vivo activities, pharmacokinetic profile, and the hPXR activity, which predicts the potential 3A4 induction in human, are disclosed.

To assess the outcome of patients diagnosed to have liver metastasis by ultrasonography, following curative-intent resection of colorectal adenocarcinoma.Prospective study.Regional hospital, Hong Kong.A total of 650 patients who underwent curative-intent resection of colorectal adenocarcinoma between January 2000 and December 2006.Pattern of liver recurrence, treatment and outcome after recurrence, and overall patient survival.Of the 650 patients, 553 (85%) were followed up per protocol. Of 104 patients who developed systemic recurrence, 45 (43%) had liver-only metastases. The resection rate for liver metastases was 38% (17/45). The median survival of such patients was significantly longer than those who did not undergo liver metastasectomy (50 vs 26 months, P=0.017).Our ultrasonography-based surveillance protocol was low-cost, simple, and effective in detecting asymptomatic liver metastases, so that curative-intent metastasectomy could be performed. Further prospective studies are required to determine the optimal frequency and imaging mode for surveillance, so as to improve the resectability of liver-only colorectal metastases as well as overall patient survival.

Over the past decade, the use of drug metabolism and pharmacokinetic (DMPK) parameters to optimize selection of candidates for drug development has become one of the primary focuses of research organizations involved in new drug discovery.This review will focus on the feasibility of predicting human absorption using data from a cultured Caco-2 cell system and non-clinical animals.In-house Caco-2 permeability data were compared with human absorption data from the literature. Animal absorption data obtained from current literature were also compared with human data.Using a combination of rapid in-vivo and in-vitro DMPK screens on a large array of compounds during the lead optimization process has resulted in the streamlined development of compounds that have acceptable DMPK properties. Since it is well recognized that human intestinal absorption cannot be precisely predicted by a single screening assay, it is important to utilize various in-vitro and in-vivo non-clinical studies during lead optimization in drug discovery.

Different levels of positive end-expiratory pressure (PEEP) with and without a recruitment maneuver (RM) may have a significant impact on ventilator-induced lung injury but this issue has not been well addressed.Anesthetized rats received hydrochloric acid (HCl, pH 1.5) aspiration, followed by mechanical ventilation with a tidal volume of 6 ml/kg. The animals were randomized into four groups of 10 each: (1) high PEEP at 6 cm H(2)O with an RM by applying peak airway pressure at 30 cm H(2)O for 10 s every 15 min; (2) low PEEP at 2 cm H(2)O with RM; (3) high PEEP alone; and (4) low PEEP alone.The mean arterial pressure and the amounts of fluid infused were similar in the four groups. Application of the higher PEEP improved oxygenation compared with the lower PEEP groups (P0.05). The lung compliance was better reserved, and the systemic cytokine responses and lung wet to dry ratio were lower in the high PEEP than in the low PEEP group for a given RM (P0.05).The use of a combination of periodic RM and the higher PEEP had an additive effect in improving oxygenation and pulmonary mechanics and attenuation of inflammation.

This chapter will focus on the two most commonly used high-throughput screening methods detecting cellular/bio-membrane permeability in the pharmaceutical industry: Caco-2 cells and the parallel artificial membrane permeability assay (PAMPA). Both assays have advantages and disadvantages, and it is essential to understand these limitations. Since it is well recognized that human intestinal absorption cannot be precisely predicted by a single screening assay, it is important to utilize various in vitro and in vivo preclinical studies during lead optimization in drug discovery.

In this study, in vitro systems were used to build 2 pharmacokinetic models that predict human oral bioavailability: the Caco2/hepatocyte combination model and the Caco-2/hepatocyte hybrid model. Data obtained in vitro on Caco-2 cell permeability and hepatocyte clearance are routinely used to predict the fraction of absorption after oral administration and the extent of first-pass metabolism, respectively. In the Caco-2/hepatocyte combination model, results from a Caco-2 cell permeability assay and a hepatocyte clearance assay were combined to project oral bioavailability. Comparison of oral bioavailabilities predicted by the combination model and reported oral bioavailabilities in humans for 30 marketed compounds resulted in a modest correlation (r 2 = 0.66). The Caco-2/hepatocyte hybrid model, as previously reported, joins the Caco-2 and hepatocyte clearance systems into 1 assay. Improvements to the previous model were made by incorporating an elimination phase into the Caco-2/hepatocyte hybrid model. In the new hybrid model, the compound was added to a Caco-2-containing donor compartment and allowed to permeate for 2 h to a hepatocyte-containing receiver compartment. Subsequently, to mimic an elimination phase, the donor compartment was removed, and permeated compound was incubated with hepatocytes alone for an additional 3 h. The area under the concentration versus time curve (AUC) was determined for each of the same 30 marketed compounds assessed by the combination model. A linear regression analysis comparing the in vitro AUCs and reported oral bioavailabilities in humans showed a reasonable correlation (r 2 = 0.73). This study demonstrates that the Caco-2/hepatocyte hybrid model is more favorable and further proves the potential and feasibility of using in vitro screenings for the prediction of in vivo pharmacokinetics in humans. (Journal of Biomolecular Screening 2007:1084-1091)

We have derived a novel series of neuropeptide Y (NPY) Y5 receptor antagonists from the biphenylurea 3. Cyclohexylurea 21c, a member of the series, is a potent NPY Y5 receptor antagonist that exhibits excellent pharmacokinetic parameters in rats and dogs. On chronic oral administration to diet-induced obese rats, 21c displayed an anti-obesity profile, causing a modest reduction in food intake, a significant decrease in body weight gain, a decrease in adipose mass, and an increase in lean tissue mass.