bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Anaemia on Sensory Nerve Conduction in Diabetic Peripheral Neuropathy: A Cross-sectional Study
Authors: Jhana Nirang , . Shuba
Published: March 2023

Introduction: Diabetic Peripheral Neuropathy (DPN) occurs in more than 50% of patients with Type 2 Diabetes Mellitus (T2DM). Though multi-factorial pathogenesis has been claimed for the occurrence of DPN, the exact mechanism is unclear. Recently, it was found that the prevalence of anaemia is two to three times higher in diabetic patients even with preserved renal function. Aim: To compare the sensory nerve conduction study variables such as latency (ms), amplitude (μV) and Nerve Conduction Velocity (NCV) (m/s) of the median, ulnar and sural nerves in DPN patients with anaemia to those without anaemia. Materials and Methods: This cross-sectional study was conducted in the Department of Neurology, PSG Hospital, Coimbatore, Tamil Nadu, India, December 2017 to December 2018 with 80 DPN subjects, included both males and females of age group from 35 to 70 years, grouped into those without anaemia (n=40) and those with anaemia (n=40). Subjects were considered to have anaemia based on the World Health Organisation (WHO) classification of haemoglobin. Sensory nerve conduction studies were performed on right and left median, ulnar and sural nerves. Logistic regression was performed in DPN without and with anaemia to rule out confounding variables. Independent t-test and Mann-Whitney U test were used to compare the variables between the groups with normal and skewed distribution, respectively. The p-value <0.05 was considered to be statistically significant. Results: Among 80 study participants, 38 (47.50%) were male and 42 (52.50%) were female. About 20 (50%) were male and 20 (50%) were female in group A (DPN without anaemia). Seventeen (42.50%) were male and 23 (57.50%) were female in group B (DPN with anaemia). Among DPN subjects with anaemia, 57.50% had mild anaemia and 42.50% had moderate anaemia. In the present study, normocytic normochromic anaemia was the predominant form of anaemia seen. NCV of right median nerve, right ulnar nerve, right sural nerve and left sural nerve were significantly reduced in DPN with anaemia when compared to DPN without anaemia with values <0.001, <0.001, 0.001 and <0.001, respectively. The amplitude of right sural nerve and left sural nerve were significantly reduced in DPN with anaemia, compared to DPN without anaemia with p-values <0.001 and 0.017, respectively. Conclusion: DPN patients with anaemia had lower NCV and amplitude of sensory nerves, when compared to those without anaemia. Hence, even mild to moderate anaemia could be a possible risk factor that exacerbates the severity of DPN.
Improving Access to Substance Use Treatment for Women: The Integrated Relapse Prevention Program
Authors: Yoon Rosanra , Furlong April , Bloomenfeld Julia , Biasia Karina , Innis Sarah , Coombs Michelle
Published: March 2023

Canadian women with alcohol use disorder have limited access to anti-craving medication, despite its effectiveness in reducing alcohol use. This article describes the results of a pilot program developed to improve access to integrated medical assessment and management of anti-craving medication and traumainformed relapse prevention counselling in a community setting.
Redesigning Old Dhaka Central Jail into Urban Open and Social Interaction Space for People
Authors: Shad Shah Md. Hasin
Published: March 2023

Urban open space is essential in an urban area. It helps to improve the general health and well-being of the residents. Dhaka is one of the fastest-growing cities globally but the numbers of urban open spaces in this city are decreasing day by day. Old Dhaka is the oldest and most densely populated area in the city of Dhaka. Here, people do not have minimum urban open space for social interaction and for creating a neighborhood. Old Dhaka Central Jail is an abandoned jail that is situated in the Chawkbazar area of old Dhaka; the jail is currently identified as a “Brown Field” in this area. Though the space is abandoned, the jail also has some historical structures and significance. This paper examined the way to convert the jail area into an urban open space for people to interact socially. A broad field survey and observation survey were done to develop morphological analysis and also a literature study was done to develop some strategies for spatial framework.  The goal of this paper is not only creating open spaces but also proposing a process of preserving historic structures. The design has been conceptualized in a process that also solves many problems of the surrounding area.
Clinical and Dermoscopic Features of Winer's Nodular Solitary Calcinosis
Authors: Asermouh Marwa , Maouni Safae , Khabba Chaimae Ait , Znati Kaoutar , Senouci Karima , Meziane Mariame
Published: March 2023

Aims: Solitary nodular calcinosis of Winer is a rare and benign form of localized idiopathic cutaneous calcinosis. Its dermoscopic features may be useful for early diagnosis, but have never been described in the literature to our knowledge.

Case Report: A 5-year-old child presented to our clinic with a  2 years history of a painless keratotic  and warty nodule located in the helix of the right ear. A wart was suspected and treated without any improvement. Dermoscopy was performed and showed peripheral white deposits suggestive of Winer's calcinosis, motivating an excision whose histological examination confirmed the diagnosis.

Discussion: The subepidermal calcified nodule has been rarely described in the literature. It is not known to be associated with a disorder of phosphocalcium metabolism or other systemic diseases. Pathogenic hypotheses include calcification of preexisting skin structures, mast cell degranulation with secondary calcinosis, or prior trauma. Surgical excision with histopathological confirmation is necessary to show the dermal calcium deposits, which are usually amorphous and granular and may be surrounded by a lymphohistiocytic infiltrate or giant cells. Nevertheless, dermatoscopic evaluation can aid in rendering a timely diagnosis by showing these whitish dermal deposits.

Conclusion: The diagnosis of Winer's nodular calcinosis has always been based on histology, but the dermoscopy described here for the first time is so suggestive that it can be used to save time and exclude other differential diagnoses.
Effect of Long-Term Organic Cropping Systems on Physico-Chemical Properties of the Soils of Indian Punjab
Authors: Kaur Jaskirandeep , Singh Didar
Published: March 2023

Organic farming is gaining momentum because of awareness among consumers for quality food. The long term effects of organic cropping systems on soil quality yet not have been studies in details. Therefore the present study the long term effect of five cropping systems viz. Poplar (Populus deltoids) + turmeric (Curcuma longa), sugarcane (Saccharum officinarum Linn )+ bottle gourd (Lagenaria siceraria) - broccoli (Brassica oleracea), basmati rice (Oryza sativa) - wheat (Triticum aestivum), sugarcane fodder and maize (Zea mays) + summer moong (Vigna radiate) - wheat on soil physico-chemical properties was studied at Bhagat Puran Singh Natural Agriculture Farm and Research Centre, Amritsar, Punjab (31.5730 N, 75.0660 E). The depth wise soil samples from these cropping systems were collected after rabi (2018-19) and kharif (2019) seasons. Poplar + turmeric cropping system has significantly higher soil organic carbon(SOC), soil carbon stock(SOCS), soil aggregate associated carbon(AAC), water stable soil aggregates (WSA) and mean weight diameter(MWD) of soil than other cropping systems. Sugarcane fodder cropping system has significantly higher soil pH than other cropping systems while basmati rice - wheat cropping system has significantly lower electrical conductivity (EC) and higher soil bulk density (BD) compared to other cropping systems. In the top soil (0-7.5 and 7.5-15 cm depths) SOC, SOCS, AAS, EC, WSA and MWD were significantly higher than subsurface layers (15-22.5 cm and 22.5-30 cm depth) whereas soil pH and BD were significantly lower in surface soil than subsurface soil.
A Systematic Review of Pattern and Prevalence of Cannabis Use among Transporters and Associated Road Traffic Accidents
Authors: Nkporbu A. K. , Stanley P. C.
Published: March 2023

Background: Cannabis (marijuana), while being prohibited in many countries, is the most commonly used illicit drug worldwide (WHO, 1997).  "Cannabis-impaired driving" refers to the impairment brought on by 9-tetrahydrocannabinol's (THC) cognitive and psychomotor effects, which have a negative impact on a driver of a motor vehicle after THC ingestion. In contrast, a "cannabis-positive driver" is a person who operates a motor vehicle while exhibiting driving impairments due to any measurable THC concentration in blood, oral fluid, or urine. A driver is considered to be "driving under the influence of cannabis" (DUIC) if their cognitive or psychomotor abilities are significantly impaired and their blood, oral fluid, or urine contains a specific amount of THC.

Aim: This study aimed at conducting a systematic review of pattern and prevalence of cannabis use among transporters and the associated road traffic accidents.

Design: A systematic review.

Data Sources: Systematic search for worldwide published literature from PubMed, PsycINFO, EMBASE, Google Scholar, Science Direct, Cochrane Library and Medline databases.

Study eligibility criteria: These studies provided techniques and/or measurements of the frequency and pattern of cannabis use among transporters and the related traffic incidents.

Data extraction: The first reviewer extracted the data, and the second reviewer verified it. Both reviewers individually critiqued each of the identified papers. Data was extracted from each eligible study (including author, title, year, and study setting) following the Preferred Reporting Items on Systematic Reviews and Meta-Analysis (PRISMA). These data abstraction forms were examined, and studies that satisfied the criteria were added to the meta-analysis.

Findings: Only 10 studies met all of the inclusion criteria out of the 2,251 papers that were recovered after looking at the titles and abstracts (where an abstract was not available, the article was still counted).

Conclusion: The study emphasizes the significance of education, law enforcement, and routine drug testing, reducing bribery among federal prosecutors, and influencing the accessibility of cannabis and other psychiatric substances as assessments for preventing substance cruising and restricting road traffic accidents. It also highlights areas where the study's findings and the scientific literature on risk factors for traffic accidents and preventative measures overlap. To increase acceptance and improve results, it is crucial to incorporate lay perspectives into road safety policies and initiatives.
A Comprehensive Review of Risk Management in the Medical Device Industry
Authors: Sharma Akash , Luthra Gaurav
Published: March 2023

The medical device industry is highly regulated, with a focus on ensuring the safety and effectiveness of medical devices. Risk management is a critical aspect of the medical device industry, involving the identification, assessment, and control of potential risks associated with medical devices. This paper provides a comprehensive review of risk management in the medical device industry, including its history, current regulatory framework, and key principles and processes. The paper examines the different types of risks associated with medical devices and explores various risk management techniques and tools used by medical device manufacturers. Additionally, the paper discusses the importance of post-market surveillance and risk monitoring, as well as the role of clinical evaluations in risk management. The paper concludes by highlighting emerging trends and future directions in risk management for the medical device industry. Overall, this comprehensive review provides a valuable resource for medical device manufacturers, regulators, and other stakeholders interested in risk management in the medical device industry.
The effect of glutathione on the ATPase activity of MRP1 in its natural membranes
Authors: Hooijberg J.H , Pinedo H.M , Vrasdonk C , Priebe W , Lankelma J , Broxterman H.J
Published: July 2002

The transport mechanism by which the multidrug resistance protein 1 (MRP1) effluxes cytotoxic agents out of cells is still not completely understood. However, the cellular antioxidant glutathione (GSH) has been shown to have an important role in MRP1‐mediated drug transport. In this study we show that GSH stimulates the ATPase activity of MRP1 in a natural plasma membrane environment. This stimulation was dose‐dependent up to 5 mM. The MRP1 substrates vincristine and daunorubicin do not induce MRP1 ATPase activity. In addition, the effect of GSH on the MRP1 ATPase activity is not increased by daunorubicin or by vincristine. In contrast, a GSH conjugate of daunorubicin (WP811) does induce the ATPase activity of MRP1. In the presence of GSH the effect of WP811 was not significantly increased. Finally, (iso)flavonoid‐induced MRP1 ATPase activity is not synergistically increased by the presence of GSH. In conclusion, we show that GSH has no apparent influence on the ATPase reaction induced by several MRP1 substrates and/or modulators. The subclasses of molecules had different effects on the MRP1 ATPase activity, which supports the existence of different drug binding sites.
Stringent Regulation and High‐Level Expression of Heterologous Genes in Escherichiacoli Using T7 System Controllable by the araBAD Promoter
Authors: Chao Yun‐Peng , Chiang Chung‐Jen , Hung Wen‐Bin
Published: July 2002

The recombinant Eschreichia coli strain BL21 (BAD) was constructed to carry a chromosomal copy of T7 gene 1 fused to the araBAD promoter. To further characterize this expression system, strain BL21 (BAD) was transformed with the plasmid containing the carbamoylase gene from Agrobacterium radiobacter driven by the T7 promoter. Upon induction with l‐arabinose, recombinant cells produced 100‐fold increase in carbamoylase activity in comparison with uninduced cells on M9 semidefined medium plus glycerol. This protein yield accounts for 30% of total cell protein content. In addition, it was found that after 100 generations the plasmid harboring the carbamoylase gene remained firmly stable in strain BL21 (BAD), but its stability dropped to only 20–30% in strain BL21 (DE3), a commercial strain bearing T7 gene 1 regulated by the lacUV5 promoter in its chromosome. In an attempt to enhance the total protein yield, fed‐batch fermentation process was carried out using a two‐stage feeding strategy to compartmentalize cell growth and protein synthesis. In the batch fermentation stage, the culture was grown on glucose to reach the stationary growth phase. Subsequently, glycerol was fed to the culture broth and l‐arabinose was augmented to induce protein production when cells entered the late log growth phase. As a result, a carbamoylase yield corresponding to 5525 units was obtained, which amounts to a 337‐fold increase over that achieved on a shake‐flask scale. Taken together, these results illustrate the practical usefulness of T7 system under control of the araBAD promoter for heterologous protein production.
Expanded Application of a Two‐Phase Partitioning Bioreactor through Strain Development and New Feeding Strategies
Authors: Vrionis H. A. , Kropinski A. M. , Daugulis A. J.
Published: July 2002

This research demonstrated the microbial treatment of concentrated phenol wastes using a two‐phase partitioning bioreactor (TPPB). TPPBs are characterized by a cell‐containing aqueous phase and an immiscible and biocompatible organic phase that partitions toxic substrates to the cells on the basis of their metabolic demand and the thermodynamic equilibrium of the system. Process limitations imposed by the capability of wild‐type Pseudomonas putida ATCC 11172 to utilize long chain alcohols were addressed by strain modification (transposon mutagenesis) to eliminate this undesirable biochemical characteristic, enabling use of a range of previously bioavailable organics as delivery solvents. Degradation of phenol in a system with the modified strain as catalyst and industrial grade Adol 85 NF (primarily oleyl alcohol) as the solvent was demonstrated, with the system ultimately degrading 36 g of phenol within 38 h. Volumetric phenol consumption rates by wild type P. putida ATCC 11172 and the genetically modified derivative revealed equivalent phenol degrading capabilities (0.49 g/L·h vs 0.47 g/L·h respectively, in paired fermentations), with the latter presenting a more efficient remediation option due to decreased solvent losses arising from the modified strainapos;s forced inability to consume the delivery solvent as a substrate. Two feeding strategies and system configurations were evaluated to expand practical applications of TPPB technology. The ability to operate with a lower solvent ratio over extended periods revealed potential for long‐term application of TPPB to the treatment of large masses of phenol while minimizing solvent costs. Repeated recovery of 99% of phenol from concentrated phenol solutions and subsequent treatment within a TPPB scheme demonstrated applicability of the approach to the remediation of highly contaminated “effluents” as well as large masses of bulk phenol. Operation of the TPPB system in a dispersed manner, rather than as two distinct phases, resulted in volumetric consumption rates similar to those previously achieved only in systems operated with enriched air.
Development of an Antibody‐Based Assay for Determination of Baculovirus Titers in 10 Hours
Authors: Kwon M. S. , Dojima T. , Toriyama M. , Park Enoch Y.
Published: July 2002

The baculovirus expression system has been used to produce large amounts of biologically active proteins by infecting insect cells with a recombinant baculovirus expressing the target protein. For an efficient expression of the target protein, it is necessary to infect insect cells with an adequate amount of virus. However, current methods are time‐consuming and either have technical difficulties or are limited as a result of virus expression mechanism using a reporter gene. A novel method is developed to yield virus titers in 10 h that is easy to perform using 96‐well plates and applicable to both any Autographa californica nucleopolyhyderovirus (AcNPV) and Bombyx mori nucleopolyhedrovirus (BmNPV)‐based recombinant baculovirus. This assay uses an antibody to a DNA‐binding protein to detect the infected cells via immunostaining. The titer is determined by counting foci produced as a result of infection of the virus under a fluorescent microscope. The required incubation period was shortened considerably because infected cells expressed viral antigens at the post‐infection time of 4 h. Therefore, 10 h was enough to estimate the virus titer including virus infection time, insect cell culture, and estimation of virus titer. Titers determined using this immunological assay are comparable, both in value and validity, to those obtained using a traditional method, provided that the stocks have titers above 103 pfu/mL.
Short synthetic glycopeptides successfully induce antibody responses to carcinoma‐associated Tn antigen
Authors: Vichier‐guerre S. , Lo‐man R. , Bay S. , Deriaud E. , Nakada H. , Leclerc C. , Cantacuzène D.
Published: July 2002

Abstract: Glycopeptides containing a tumor‐associated carbohydrate antigen (mono‐, tri‐ or hexa‐Tn antigen) as a B‐cell epitope and a CD4+ T‐cell epitope (PV: poliovirus or TT: tetanus toxin) were prepared for immunological studies. Several Tn antigen residues [FmocSer/Thr (α‐GalNAc)‐OH] were successively incorporated into the peptide sequence with unprotected carbohydrate groups. The tri‐ and hexa‐Tn glycopeptides were recognized by MLS 128, a Tn‐specific monoclonal antibody. The position of the tri‐Tn motif in the peptide sequence and the peptide backbone itself do not alter its antigenicity. As demonstrated by both ELISA and FACS analysis, the glycopeptides induced high titers of anti‐Tn antibodies in mice, in the absence of a carrier molecule. In addition, the generated antibodies recognized the native Tn antigen on cancer cells. The antibody response obtained with a d‐(Tn3)‐PV glycopeptide containing three α‐GalNAc‐d‐serine residues is similar that obtained with the Tn6‐PV glycopeptide. These results demonstrate that short synthetic glycopeptides are able to induce anticancer antibody responses.
Oxidative stress and erythrocyte damage in Kenyan children with severe Plasmodium falciparum malaria
Authors: Griffiths Michael J. , Ndungu Francis , Baird Karen L. , Muller David P. R. , Marsh Kevin , Newton Charles R. J. C.
Published: July 2002

Anaemia causes significant morbidity in children with Plasmodium falciparum malaria, but the mechanism(s) are unclear. During malarial infection, increased reactive oxygen species (ROS) are generated that may contribute to erythrocyte damage and anaemia. This study measured the concentrations of α‐tocopherol in plasma and erythrocyte membranes, and the percentage polyunsaturated fatty acid composition (%PUFA) (an indirect marker of ROS damage) in erythrocyte membranes in children with severe P. falciparum malaria from Kilifi, Kenya, and asymptomatic children from the same district. Malarial subjects were stratified into complicated malaria and malaria anaemia. Results demonstrated significant reductions in erythrocyte membrane α‐tocopherol concentration (1·63 ± 0·16 versus 3·38 ± 0·18 μmol/mg protein; P < 0·001) and total %PUFA (30·7 ± 0·49 versus 32·8 ± 0·44% P < 0·005) for the malarial subjects (non‐stratified) compared with controls. Malarial subjects showed a significant positive correlation between membrane α‐tocopherol and haemoglobin concentrations (P < 0·005 r = 0·63 complicated malaria group; P < 0·05 r = 0·36 non‐stratified data). There were no significant differences in plasma α‐tocopherol concentration between malaria patients and controls. In conclusion, malarial infection may be associated with oxidative damage and reduced α‐tocopherol reserve in the erythrocyte membrane, suggesting that local antioxidant depletion may contribute to erythrocyte loss in severe malaria. Erythrocyte membrane α‐tocopherol appeared a better indicator of ROS exposure than plasma.
Lymphocyte proliferation modulated by glutamine: involved in the endogenous redox reaction
Authors: Chang W K , Yang K D , Shaio M F
Published: July 2002

Decreased glutamine concentrations are found during catabolic stress and are related to susceptibility to infections. However, little is known about the mechanism of glutamine modulation of lymphocyte functions. Glutamine is not only an important energy source in mitochondria, but is also a precursor of glutamate, which is used for cellular glutathione (GSH) biosynthesis in lymphocytes. In this study, we investigated the effects of glutamine on the redox reaction during lymphocyte proliferation. Peripheral blood mononuclear cells, obtained from healthy adult volunteers, were cultured and stimulated by phytohaemagglutinin (PHA) in the presence of different glutamine concentrations. Cells were harvested and prepared for analysis of lymphocyte proliferation, cell cycle propagation, intracellular glutathione levels and reactive oxygen species (ROS) production. We found that glutamine supplementation significantly enhanced PHA-stimulated lymphocyte proliferation and propagation of the cell cycle from the G1 to S and G2/M phases. Glutamine also enhanced production of both intracellular ROS and GSH levels in PHA-stimulated lymphocytes. Flow cytometric analysis by the mercury orange staining method showed that glutamine significantly enhanced intracellular non-protein thiols in PHA-stimulated CD4+, but not CD8+ lymphocyte subsets. Furthermore, intracellular GSH detected by monochlorobimane dye probe showed that glutamine enhanced GSH both in PHA-stimulated CD4+ and CD8+ lymphocyte subsets. Inadequate glutamine supplementation resulted in decreased lymphocyte proliferation in association with decreased levels of intracellular GSH. Addition of exogenous GSH significantly enhanced lymphocyte proliferation, whereas blockade of GSH synthesis enhanced ROS production and suppressed lymphocyte proliferation. These results suggest that the modulation of PHA-stimulated lymphocyte proliferation by glutamine is closely related to the maintenance of appropriate intracellular redox status.
Genetic studies of a family with hereditary hyperparathyroidism–jaw tumour syndrome
Authors: Wassif Wassif S. , Farnebo Filip , Tean Teh Bin , Moniz Caje F. , Li Fang‐Yuan , Harrison John D. , Peters Timothy J. , Larsson Catharina , Harris Philip
Published: July 2002

BACKGROUND AND OBJECTIVES

Familial hyperparathyroidism may occur as familial isolated hyperparathyroidism (FIHP) or as part of an inherited syndrome, in particular multiple endocrine neoplasia types 1 and 2 A (MEN1, MEN2A) and hyperparathyroidism–jaw tumour (HPT–JT) syndrome. The localization of the genes responsible for these syndromes has enabled genetic screening of families with primary hyperparathyroidism (PHPT) to be carried out. This has important clinical implications in terms of individual follow‐up and management. We previously reported a large FIHP family with an increased risk of parathyroid cancer and excluded its linkage to MEN1, MEN2 and PTH genes. Here we re‐analysed this family and performed genetic linkage to the HPT–JT locus in chromosome 1q21‐q32. Loss of heterozygosity studies of 1q21‐q32, 11q13 and X chromosome were also performed.

PATIENTS AND DESIGN

We studied 19 family members, aged 6–63 years. High molecular weight DNA was isolated from peripheral blood samples from 17 family members. For the two deceased individuals, DNA was extracted from normal paraffin embedded tissues.

MEASUREMENTS

All individuals (except two deceased patients) had serum corrected calcium, inorganic phosphate, intact PTH, prolactin and various pancreatic hormones, measured on fasting blood samples. Twenty microsatellite markers were examined for the 1q21‐q32 region, the locus for the HPT–JT gene. Genetic polymorphisms were determined by polymerase chain reaction amplification of genomic DNA and genetic linkage analysis was performed. Loss of heterozygosity studies were performed using paraffin‐embedded parathyroid tissues from four affected members.

RESULTS

Seven of the eight affected family members included in this study had biochemical evidence of PHPT and surgically proven parathyroid tumours. Indication of linkage of the disease to the HPT–JT locus was demonstrated with a maximum lod score of 2.32 by two‐points linkage analysis. Linkage data were supported by multi‐point analysis which gave a maximum lod score of 2.7. Meiotic recombinations detected in one affected individual narrowed the region to 26 cM. As a result of the genetic findings, we re‐screened the living family members by orthopantomograph and renal ultrasound, and identified two jaw lesions in two gene carriers. One affected family member demonstrated polycystic kidney disease, thus establishing the association between the two conditions. A reduced penetrance of HPT in females was evident, in agreement with our previous study. No allelic deletion was detected in any tumour at 1q21‐q32, 11q13 or X chromosome.

CONCLUSIONS

This study illustrates the usefulness and importance of genetic studies in familial isolated hyperparathyroidism families. Our clinical and genetic findings indicate that this previously reported familial isolated hyperparathyroidism family has hyperparathyroidism–jaw tumour syndrome.
Flow Cytometry Analysis of Milk and Peripheral Blood Cells from Goats during Lactation*
Authors: Winnicka A. , Kluciński W. , Hoser G. , Sikora J. , Kawiak J.
Published: July 2002

Cells from goat’s milk and peripheral blood taken during the lactation period were analysed by flow cytometry. The investigated cells were populations of leucocytes, lymphocyte subpopulations (T, T‐helper, T‐cytotoxic, B, WC1‐N2) and all MHC class II positive cells. Labelling of cells was performed on whole blood and milk cell suspensions. Statistically significant differences were found between percentages of B and WC1‐N2 lymphocytes and MHC II positive cells from peripheral blood during the lactation period and all of examined milk cells during the same time.
Embryology and Seed Development of Paepalanthus sect. Actinocephalus (Koern.) Ruhland (Eriocaulaceae)
Authors: Scatena V. L. , Bouman F.
Published: July 2002

Abstract: The embryology and seed structure of Paepalanthus sect. Actinocephalus species were studied. The embryological and structural seed characters fit well with those of the other commelinaceous families. Within the Commelinales sensu Dahlgren, Eriocaulaceae and Xyridaceae represent two embryologically close families. In Paepalanthus sect. Actinocephalus the ovule is orthotropus, bitegmic, and tenuicellate with a micropyle formed by the inner integument. The seeds are endotestal. The outer cell layer of the testa and the outer periclinal wall of the endotesta disintegrate during development. The endotegmen is tanniniferous. The outer layer of the tegmen becomes compressed and is no longer recognizable in the mature seed. The seeds are operculate.
Laser-induced damage in beta-barium metaborate
Authors: Nakatani H. , Bosenberg W. R. , Cheng L. K. , Tang C. L.
Published: July 2002

Laser-induced damage in beta-barium metaborate (BBO) has been investigated at the wavelengths of 1064, 532, and 355 nm. The single-shot bulk damage threshold of BBO is 50 GW/cm2 at 1064 nm, 48 GW/cm2 at 532 nm, and 25 GW/cm2 at 355 nm. Damage by multiple pulse irradiation has also been studied and the probabilistic nature of the damage is discussed. Brief comments are also made on the morphology of the damage.
Determination of nonradiative surface layer thickness in quantum dots etched from single quantum well GaAs/AlGaAs
Authors: Clausen E. M. , Craighead H. G. , Worlock J. M. , Harbison J. P. , Schiavone L. M. , Florez L. , Van der Gaag B.
Published: July 2002

Low-temperature cathodoluminescence spectroscopy was used to investigate the luminescence efficiency of reactive ion etched quantum dots, varying in diameter from 200 μm down to 60 nm. The luminescence efficiency was found to be degraded both with decreasing nanostructure size and with increasing etch depth. A solution to the standard model for diffusion and recombination was applied to the data to determine the surface recombination velocity S. We found that for dots smaller than the diffusion length, the standard diffusion model becomes insensitive to the value of S and fails to predict that there is a size of dot in which the luminescence is completely extinguished. To understand qualitatively the luminescence degradation in etched nanostructures we describe a damage layer thickness ξ. The value of ξ determines the smallest quantum structure that will still emit light. We show that ξ increases with increasing etch depth and is therefore dependent on etching conditions.
Picosecond time-resolved surface-lattice temperature probe
Authors: Elsayed-Ali H. E. , Herman J. W.
Published: July 2002

Picosecond reflection high-energy electron diffraction is used as a time-resolved surface-lattice temperature probe. A picosecond laser pulse is split into two beams. The first interacts with the sample. The second activates the cathode of an electron gun creating a collimated and focused electron pulse that is well synchronized with the heating laser pulse. The electron pulse is used to generate a reflection high-energy electron diffraction pattern of the sample. Since heating results in an intensity reduction of the elastically scattered electrons (Debye–Waller effect), the diffraction pattern provides information on the surface temperature as well as structure. Time-resolved measurements of the picosecond laser-heated surface show general agreement with a heat diffusion model.
Substrate step-edge YBa2Cu3O7 rf SQUIDs
Authors: Daly K. P. , Dozier W. D. , Burch J. F. , Coons S. B. , Hu R. , Platt C. E. , Simon R. W.
Published: July 2002

We have developed a technique which permits high-yield fabrication of microbridges and low noise YBa2Cu3O7 superconducting quantum interference devices (SQUIDs) in epitaxial thin films. These SQUIDs operate over a wide temperature range extending from 4 K to close to the superconducting transition temperature. Measurements of an rf SQUID operating at 77 K give a peak-to-peak flux sensitivity of 36 μV/Φ0 and a flux noise at 10 Hz of 1.5× 10−4 Φ0/√Hz. Device yields over 80% have been obtained.
Comparison of bulk and quantum wire photodetectors
Authors: Crawford D. L. , Nagarajan R. L. , Bowers J. E.
Published: July 2002

A theoretical comparison of the operating characteristics of p-i-n GaAs/AlGaAs photodetectors incorporating either bulk or quantum wire absorbing regions is presented in an effort to realistically compare both the bandwidth and the quantum efficiency of these devices. Devices utilizing quantum wire absorbing regions may have enhanced operating characteristics assuming increased absorption and saturated carrier drift velocities can be realized in these quantized structures.
Room-temperature short-period transient grating measurement of perpendicular transport in GaAs/AlGaAs multiple quantum wells
Authors: Norwood D. P. , Swoboda H.-E. , Dawson Martin D. , Smirl Arthur L. , Andersen D. R. , Hasenberg T. C.
Published: July 2002

A short-period transient grating technique with 100 fs resolution is used to study room-temperature perpendicular transport over nanometer dimensions in GaAs/Al0.3Ga0.7As multiple quantum wells (MQWs) whose barrier widths range from 1.4 to 15 nm. With decreasing barrier width, a transition from transport dominated by thermal over-barrier hopping to that dominated by tunneling is observed. For the thinnest barriers, measurements are in good quantitative agreement with simple rate equations describing tunneling, and the measured grating decay rates are related to the microscopic tunneling rates. By comparison, for MQWs with thick barriers, the transport shows no barrier width dependence, and a room-temperature over-barrier hopping rate is extracted.
Switchable bicolor (5.5–9.0 μm) infrared detector using asymmetric GaAs/AlGaAs multiquantum well
Authors: Martinet E. , Rosencher E. , Luc F. , Bois Ph. , Costard E. , Delaître S.
Published: July 2002

Electrical switching of a bispectral infrared photoconductor is demonstrated with GaAs/AlGaAs asymmetric step multiquantum wells, presenting bound-to-bound (tunable 8.5–9.0 μm) and bound-to-extended (≊5.5 μm) intersubband transitions of similar oscillator strengths. The bound-to-bound photoresponse is switched on by applying an electric field of sufficient magnitude to permit the collection of the photoexcited bound electrons by tunneling.
Giant magnetoresistance in magnetically inhomogeneous thin films
Authors: Tsoukatos A. , Wan H. , Hadjipanayis G. C. , Li Z. G.
Published: July 2002

Giant magnetoresistance (GMR) has been observed in thin films of Fe and Co in Ag. The best results were obtained in the Ag-rich samples with a maximum value of 25% in Co20Ag80 at 30 K. The GMR values are slightly increased upon annealing. Magnetic data show a magnetic transition below room temperature which may be due to spin-glass type of behavior. These results are consistent with the microstructure studies which showed a single face centered cubic phase, with very fine grains. Upon annealing separation of the two components is achieved with substantial grain growth.
Copper diffusion in amorphous thin films of 4% phosphorus-silcate glass and hydrogenated silicon nitride
Authors: Gupta D. , Vieregge K. , Srikrishnan K. V.
Published: July 2002

We have carried out direct Cu diffusion measurements in amorphous thin films of: (a) 4% phosphorus silicate glass and (b) hydrogenated silicon nitride. Thin films of 0.5 μm thickness were grown onto oxidized Si wafers by a chemical vapor deposition technique. 67Cu radiotracer diffusion techniques combined with microdepth profiling by sputtering with neutralized Ar atoms of 400–500 eV energy have been used. The 67Cu diffusion coefficients in 4% P-Si glass and in SiN:16 at. % H films in the temperature range of 227–550 °C are described by: (a) 5.3 ×10−11 exp (−0.5 eV/kT) and (b) 4×10−6 exp (−1.1 eV/kT) cm2/s, respectively. To assure reliability, the extent of Cu diffusion should be considered in device design and subsequent processing.
Growth of epitaxial Pb(Zr,Ti)O3 films by pulsed laser deposition
Authors: Lee J. , Safari A. , Pfeffer R. L.
Published: July 2002

Lead zirconate titanate (PZT) thin films with a composition near the morphotropic phase boundary have been grown on MgO (100) and Y1Ba2Cu3Ox (YBCO) coated MgO substrates. Substrate temperature and oxygen pressure were varied to achieve ferroelectric films with a perovskite structure. Films grown on MgO had the perovskite structure with an epitaxial relationship with the MgO substrate. On the other hand, films grown on the YBCO/MgO substrate had an oriented structure to the surface normal with a misorientation in the plane parallel to the surface. The measured dielectric constant and loss tangent at 1 kHz were 670 and 0.05, respectively. The remnant polarization and coercive field were 42 μC/cm2 and 53 kV/cm. A large internal bias field (12 kV/cm) was observed in the as-deposited state of the undoped PZT films.
Monochromatic all-optical gate with 1 ps response time
Authors: Paye J. , Hulin D.
Published: July 2002

A semiconductor nonlinear Fabry–Perot based on the optical Stark nonlinearity is designed as an optical gate. The device is driven by 1.2 ps light pulses with a spectrum narrower than the transmission resonance peak of the device to allow cascaded operation. One picosecond switching-on and -off times are demonstrated with 5:1 contrast ratio, in single-wavelength operation. Owing to its planar structure and ultrafast switching time, this device is the fastest all-optical gate for monochromatic parallel processing ever reported.
High temperature characteristics of InGaAsP/InP laser structures
Authors: Temkin H. , Coblentz D. , Logan R. A. , van der Ziel J. P. , Tanbun-Ek T. , Yadvish R. D. , Sergent A. M.
Published: July 2002

We investigate the high temperature performance of conventional separate confinement and lattice matched and compressively strained multi-quantum-well InGaAsP lasers emitting at 1.3 μm. Low threshold buried heterostructure lasers operate reproducibly at temperatures as high as 130 °C. The rate of threshold change with temperature is described by T0∼45°–55° for both conventional and quantum well lasers. The rate of change is not influenced by any modifications in the active layer structure. In contrast, excellent correlation is observed between the active layer structure, parametrized as the threshold gain, and the peak cw operating temperature.
Mesoscopic self-assembly of gold islands on diblock-copolymer films
Authors: Morkved T. L. , Wiltzius P. , Jaeger H. M. , Grier D. G. , Witten T. A.
Published: July 2002

We describe the fabrication and characterization of self-assembled gold island arrays on diblock-copolymer thin films. The natural tendency of these polymers to form ordered phases is used to induce selective aggregation of evaporated gold metal during an annealing process. We obtain well-defined, nanoscale island arrays aligned with one of the copolymer blocks. Near perfect segregation is achieved between the two domains. Two types of diblock-copolymer systems are discussed, together with the resulting island patterns.
Superconducting readout of semiconductor memory at liquid nitrogen temperature
Authors: Hilbert Claude , Ghoshal Uttam , Kroger Harry , Martens Jon S. , Hietala V. M. , Plut T. A.
Published: July 2002

The discovery of high-temperature superconducting materials raises the possibility of operating semiconducting and superconducting circuits at the same temperature in intimately hybridized devices and circuits. We report the experimental readout of standard CMOS memory cells using high-temperature superconducting flux flow devices at 77 K. Significant reduction in access times below that achievable with cryogenic CMOS alone was measured; a 4.5-ns access time was achieved on a 1-μm CMOS static random access memory. These results obtained using nonoptimized, separate superconductor, and semiconductor chips demonstrate the potential of hybrid superconductor-semiconductor memories for speed and power improvements over pure semiconductors operated at cryogenic temperatures.
Growth of high quality single-domain single-crystal films of PbTiO3
Authors: Li Z. , Foster C. M. , Guo D. , Zhang H. , Bai G. R. , Baldo P. M. , Rehn L. E.
Published: July 2002

Single-crystal films of PbTiO3 have been deposited on (100) SrTiO3 substrates by metalorganic chemical vapor deposition. X-ray diffraction spectra and transmission electron microscopy images revealed that the development of 90° domains was directly related to the thickness of the film. Single-domain, single-crystal films were obtained for film thickness less than 150 nm. The minimum yields of the films in ion-channeling experiments were only 3 %, similar to that of a perfect single crystal. The ordinary refractive index of the film measured by optical waveguiding experiment was also the same as that of PbTiO3 single crystals.
Synthesis of superconducting Pb-doped HgBa2CaCu2Oy films by laser ablation and post-annealing
Authors: Higuma Hiroko , Miyashita Shoji , Uchikawa Fusaoki
Published: July 2002

Superconducting Pb-doped HgBa2CaCu2Oy films have been successfully synthesized on the (100) SrTiO3 substrate by laser ablation using a Pb-doped Hg-1212 target and post-annealing. The as-deposited film was post-annealed with a pellet of the same powders as those of the target at 760 °C for 20 min in an evacuated quartz tube. The obtained film exhibited the (00n) oriented x-ray diffraction pattern of the Hg-1212. The superconducting transition temperature, Tczero, was 117 K. Anisotropy of magnetization, M(T) and M-H curves in the directions of two different fields was confirmed.
Influence of the As overpressure during the molecular beam epitaxy growth of Si-doped (211)A and (311)A GaAs
Authors: Pavesi L. , Henini M. , Johnston D.
Published: July 2002

Si-doped (211)A and (311)A GaAs samples grown by molecular beam epitaxy (MBE) with various growth As pressures have been studied. Hall effect measurements have revealed that the doping changes from p to n type by increasing the As pressure. The transition As pressure is lower for the (211)A than for the (311)A surfaces. Photoluminescence measurements have shown that by increasing the As pressure, arsenic vacancy defects are changed into pairs of Ga vacancy and Ga antisite defects. These results are explained by considering the orientation dependence of the surface bonding and the kinetics of the MBE growth process.
Demonstration of the independence of absorptive all-optical bistabilities in reflection and luminescence
Authors: Ullrich B. , Kazlauskas A. , Kobayashi T.
Published: July 2002

The dependence on the source location of photothermal bistabilities of a thin CdS:Cu film is demonstrated by the investigation of bistability in luminescence in reflection geometry. Particularly, it is shown that the infrared portion in the reflected beam clearly exhibits contrasting bistable loops in contrast to the reflection itself. The unexpected effect is explained by the fact that bistability in luminescence is a bulk feature which is not affected by the surface region.
Thermal imbalance error and effective area in guarded hot plates with anisotropic specimens
Authors: Pham Q. T.
Published: July 2002

Analytical equations are derived for the thermal imbalance error and the correction to the heat flow area in guarded hot plates when measuring the thermal conductivity of anisotropic materials. Approximate expressions are also presented for these quantities when using circular hot plates to measure the thermal conductivity across the fibers of fibrous materials.
Negative-ion plasma sources
Authors: Sheehan D. P. , Rynn N.
Published: July 2002

Three designs for negative-ion plasma sources are described. Two sources utilize metal hexafluorides such as SF6 and WF6 to scavenge electrons from electron-ion plasmas and the third relies upon surface ionization of alkali halide salts on heated alumina and zirconia. SF6 introduced into electron-ion plasmas yielded negative-ion plasma densities of 1010 cm−3 with low residual electron densities, (ne/ni∼0.01–0.05). On alumina, plasma densities of 5×109 cm−3 were obtained for CsCl, CsI, and KI and 109 cm−3 for KCl. On zirconia 1010 cm−3 densities were obtained for CsCl. For alkali halide sources, electron densities of ne/ni≲10−4 have been achieved.
Coarse tip distance adjustment and positioner for a scanning tunneling microscope
Authors: Frohn J. , Wolf J. F. , Besocke K. , Teske M.
Published: July 2002

We report on a new coarse tip distance adjustment and positioner for a scanning tunneling microscope, which was designed with ease of sample manipulation and UHV compatibility in mind. It has no mechanical connections in UHV and has been successfully used for measurements of microfaceted platinum surfaces in air and cleaved Si(111) surfaces under liquids.
Beamline and irradiation chamber for dosimetry and biology studies using synchrotron radiation
Authors: Meger C. M. , Pearson D. W. , DeLuca P. M. , Wells G. M. , Cerrina F. , Gould M. N.
Published: July 2002

Ultrasoft x rays are a useful probe for mechanistic studies of radiation damage in living cells. The highly localized energy deposition from a low energy x-ray occurs in a volume comparable to the sensitive biological targets within a cell, so that these low-energy x rays can be used as a tool to investigate radiation effects on the subcellular level. In the ultrasoft x-ray energy region the bright intensity and tunable energy selection of synchrotron radiation is unmatched by conventional sources. A beamline and irradiation chamber for dosimetry and radiation biology studies has been set up at the ES-0 exposure station of the Center for X-ray Lithography at Aladdin. The beamline includes a 10-μm-thick Be entrance window and a combination filter and single synthetically fabricated multilayer mirror for energy selection. The irradiation chamber contains another Mylar window for isolation, a two-dimensional scanning system allowing a 400-cm2 exposure area with scanning rates up to 3.5 cm/s, a rotating feedthrough system that enables motion in the third dimension, several viewports and a specially designed cell sample holder which can be filled with gases at various pressures and holds up to 18 cell culture dishes. The system has been characterized with a gas flow proportional counter to determine energy bandpass and spectral purity and a calorimeter and ionization chamber to assess photon intensity at various energies within the range 500–2000 eV.
An improved Q-Machine source
Authors: Paris P. J. , Rynn N.
Published: July 2002

The development of a new Q-plasma source is described. Emphasis is given to the novel parts of the system which have been designed to produce long term, constant density plasmas with low fluctuation levels, as well as long machine operation time. Relevant plasma parameters are obtained by laser induced fluorescence which is used as a diagnostic on the barium plasma. Plasma densities are in the range of 108 cm−3 to 1011 cm−3, with an electron temperature of about 0.2 eV, and a perpendicular ion temperature of the same magnitude. The parallel ion temperature is one half the perpendicular value.