Extracting the series resistance and effective channel length of short-channel MOSFETs at liquid nitrogen temperature

We present a simple method to extract the effective channel length and the gate voltage dependent series resistance of p-channel MOSFETs. The method is used at room and at liquid nitrogen temperatures on devices with mask channel lengths in the range of 0.6–2.0 μm. The good agreement found at 77 and 300 K between the experimental drain current-voltage characteristics of the devices and those computed from the extracted parameter verifies the validity of the method.     

Invasive squamous cell carcinoma arising from asymptomatic choristomatous cysts of the orbit. Two cases and a review of the literature

BACKGROUND: Epithelial choristomatous cysts are common orbital lesions, the most frequent of which are dermoid or epidermoid tumors. Massive enlargement or extraorbital extension of these benign lesions may occur. Malignant transformation of the epithelial lining of epidermoid cysts is rarely reported. METHODS: Two patients are presented in whom the epithelial lining of a previously asymptomatic choristomatous cyst of the orbit underwent malignant transformation to produce invasive squamous cell carcinoma. The unusual origin and clinical presentation of the lesions caused a delay in the diagnosis and therapy in both patients. Metastatic workup was negative in both patients, who underwent resection of their tumors via orbital exenteration with craniofacial resection. Reported cases of malignant transformation in analogous choristomatous cysts elsewhere in the cranium are reviewed. RESULTS: One patient is alive and well without recurrent disease 40 months postoperatively. The second patient died of a pulmonary embolus 2 months postoperatively. Autopsy showed no residual tumor. Overall, only 3 of 18 reported patients with epidermoid choristoma of the head and orbit with malignant transformation were alive when reported. CONCLUSIONS: Malignant squamous metaplasia is believed to be a rare complication of orbital dermoid or epidermoid cysts, with only two previously reported cases. However, malignant transformation is relatively frequent in analogous epidermoid cysts found elsewhere in the cranial vault, especially after incomplete excision. These reports encourage the complete removal of epithelial choristomas of the orbit.     

Identification of scalar errors-in-variables models with dynamics

The paper considers the task of identifying a causal linear dynamic system excited by stationary Gaussian zero mean noise of unknown spectrum, and given measurements of the system input and output contaminated by independent additive stationary noise signals of unknown spectra. While the solution is normally not unique, finite-dimensional parameterizations of the solution set are given (in some cases involving just one parameter), even though the various spectra may not be rational.     

An X-band acousto-optic variable delay line for radar targetsimulation

The design and characterization of a 54-μs, continuously-variable, acousto-optic (AO) delay line developed for radar testing applications is presented. Design goals for the delay line include over 10 MHz of instantaneous bandwidth, 1.2 GHz of tunable bandwidth operating at X-band, 45 dB of dynamic range, and electronically-controllable delay selection to simulate dynamic radar targets with radial range rates up to 500 m/s. In addition, the device was designed to have phase noise and spurious signal levels compatible with high performance radars. To achieve these goals, a 33-MHz center frequency variable delay line was constructed and coherent frequency translation was used to provide operation at S-band. Operating principles for this new intermediate frequency (IF) delay line are presented, and key component issues are discussed. A computer design and analysis tool is described that predicts delay line performance. Experimental results are presented at both the IF and at X-band     

Evaluation of the intraepithelial lymphocyte count in the jejunum in childhood enteropathies

Intraepithelial lymphocyte counts were evaluated in 131 jejunal mucosal biopsies taken from children with a small intestinal enteropathy arising from a variety of causes including coeliac disease, (untreated, after gluten withdrawal, and during subsequent challenge), giardiasis, cow's milk protein intolerance, and 'intractable diarrhoea'. The counts were compared with those from the biopsies of children referred for investigation but in whom no gastrointestinal disease was demonstrated and from healthy siblings of children with coeliac disease, investigated during a family study. Children with coeliac disease showed a raised count which fell after gluten withdrawal as has been demonstrated by others in adults. Lymphocytic infiltration of the epithelium increased rapidly during gluten challenge in such children, while no change was seen in those children proven ultimately not to have coeliac disease by the usually recognized criteria. In other enteropathies the range of counts was wide, overlapping with both normal and coeliac groups and indicating the nonspecificity of lymphocytic infiltration of the gut epithelium. The findings are discussed in relation to their significance and to further avenues of investigation to determine their possible diagnostic value in confirming the diagnosis of coeliac disease during gluten challenge.     

Variations in intensity, interstimulus interval, and interval between preconditioning CS exposures and conditioning with rats.

Investigated the relationship between preconditioning exposure to a stimulus later employed in conditioning as a CS and suppression of a licking response in the presence of that stimulus, in 2 experiments with a total of 216 male albino Sprague-Dawley rats. In Exp. I, a direct relationship was found between intensity of preconditioning stimulus and magnitude of suppression reduction. There was also evidence for the effects of stimulus intensity during conditioning and the operation of generalization decrement when conditioning and test stimulus intensities were not the same. Exp. II showed that preconditioning CS exposure reduced suppression to the test CS on the 1st test trial, regardless of interval between preconditioning exposures or preexposure and conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spreading the control complexity in decentralized control of interconnected systems

The problem is considered for large scale interconnected systems of designing decentralized dynamic controllers so that the sum of the orders of the local controllers is approximately the system order, while the separate controller orders are more evenly spread than permitted by the procedure of Corfmat and Morse, which generally leads to all memoriless controllers, save one of high complexity. The paper shows that under certain circumstances, it is possible to design dynamic feedback controllers for each channel which introduce stable uncontrollable or unobservable modes to the overall system, thus lowering the effective order of that system. This result is then used to spread the controller complexity.     

Intravenous RMP-7 increases delivery of ganciclovir into rat brain tumors and enhances the effects of herpes simplex virus thymidine kinase gene therapy

Herpes simplex virus thymidine kinase (HSV-tk) gene therapy for brain tumors depends on ganciclovir (GCV) and its transport across the blood-brain tumor barrier (BBTB). We examined whether RMP-7, the bradykinin analog and potent BBTB permeabilizer, could enhance the efficacy of GCV treatment of brain tumors by increasing the BBTB delivery of GCV. In vitro, a significant bystander cytocidal effect of GCV was shown in mixed HSV-tk-transduced (HSV-tk+) and control vector-transduced (HSV-tk-) C6 glioma cultures. A dose-dependent cytotoxic effect of GCV on untransformed C6 cells was also shown. In vivo, rats with 100% HSV-tk+ or 100% HSV-tk- intracerebral C6 gliomas were treated for 7 days with intravenous infusions of GCV alone or with GCV and RMP-7 (2.5 microg/kg/day). The growth of HSV-tk+ and HSV-tk- gliomas decreased with increasing doses of GCV. A high dosage (100 mg of GCV/kg/day) eradicated all HSV-tk- and HSV-tk+ tumors. An intermediate dosage (5 mg of GCV/kg/day) reduced the growth of HSV-tk- gliomas by 42% if given alone, and by 88% in combination with RMP-7. A low dosage (0.5 mg of GCV/kg/day) in combination with RMP-7 enhanced the regression of HSV-tk+ gliomas by 87% compared with GCV alone. Low-dose GCV was ineffective in HSV-tk- tumors. RMP-7 increased [3H] GCV tumoral uptake by 2.6- and 1.7-fold in the tumor center and periphery, respectively. We conclude that RMP-7 could be an important adjunctive treatment for suicide gene therapy of brain tumors, while an RMP-7/GCV combination may also have a significant antitumor effect in untransfected gliomas.     

An isotopic method for determining chemically reactive lysine based on succinylation

A method is described for the routine succinylation of proteins using [¹⁴C]succinic anhydride as a means of measuring free ?-amino groups. Maximal succinylation was achieved using 6M guanidine hydrochloride as protein solvent and an 80-fold molar excess of succinic anhydride relative to total lysine residues. Treatment with hydroxylamine (pH 13, 25°C, 5 min) removed unwanted O-succinyl esters. Succinylated protein was precipitated with trichloroacetic acid, residual label washed out with ethanol and the extent of labelling measured in a scintillation counter. The method gave close to theoretical values (n.s., P >0.05) for lysyl residues in egg white lysozyme, bovine haemoglobin, ovalbumin and bovine serum albumin but gave a low value with β-lactoglobulin and an overestimate with insulin attributable to the relatively high contribution of α- relative to ?-amino groups in this low molecular weight protein. The method gave good results for 12 soya protein samples and was shown to be very sensitive to ‘isopeptide-type’ heat damage in these samples. The results correlated well (r = 0.91) with those obtained by the well established dye-bound lysine difference procedure whereas, as could be expected, both these methods correlated poorly with total lysine determinations (r=0.69 for succinic anhydride and r=0.77 for the dye-binding method). The proposed method shows promise as a rapid procedure for the estimation of available lysine, but further studies are necessary to test its ability to measure nutritionally available lysine in all categories of heat damage.