bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of the factors which impinge on a nurse's decision to enter, stay in, leave or re‐enter the nursing profession
Authors: Moores Brian , Singh B. B. , Tun A.
Published: December 2006

As part of a wider study concerned with the changing nurse employment patterns a detailed questionnaire was completed by a total of 2325 qualified female nurses, 841 of whom were working fulltime in nursing, 634 were inactive, 678 were offering their services on a part‐time basis and 172 were working in some other occupation. In a previous article the results of the analysis conducted on the responses to the attitude questions were presented. In this paper the replies to those questions aimed at soliciting the reasons felt to have impacted on the respondent's decision to take up nursing, to stay or to leave the profession and to re‐enter the profession are analysed. As the questionnaires were distributed in the course of two projects separated by 4 years, what is of particular interest is the similarity of the two sets of results. These indicate that there is still a very high level of job satisfaction as evidenced by the extent to which nursing would be recommended to a friend or relative. The primary obvious reason for inactivity is the existence of a young child but when further intentions are explored it is clear that there is a large pool of qualified nurses keen to resume a career the main obstacle being the lack of sufficient flexibility of hours of working.
Regional specialization of rat quadriceps myosin heavy chain isoforms occurring in distal to proximal parts of middle and deep regions is not mirrored by citrate synthase activity
Authors: Kohn Tertius Abraham , Myburgh Kathryn Helen
Published: December 2006

Myosin heavy chain (MHC) isoform content and citrate synthase (CS) activities were measured in the Quadriceps femoris (QF) muscle of 18 female rats. The muscle group was divided into superficial, middle and deep, distal, central and proximal parts. MHC IIb and IIx were more abundant in superficial regions (P < 0.05) with low CS activities compared with deeper parts. The deeper parts expressed all four isoforms (MHC IIb, MHC IIx, MHC IIa and MHC I), with a concomitantly higher CS activity. MHC I, MHC IIa and MHC IIb isoform content varied significantly along the length of the deep regions. Only MHC IIb and CS activity in the proximal middle part correlated (negatively) with each other. This study showed that the QF has regional specialization and that standardization of sampling site is important. Furthermore, CS activity and MHC isoforms are only loosely associated, or not at all.
Modulation of the kinetics of evoked quantal release at mouse neuromuscular junctions by calcium and strontium
Authors: Bukharaeva Ellya A. , Samigullin Dmitry , Nikolsky Eugeny E. , Magazanik Lev G.
Published: December 2006

The effects of calcium and strontium on the quantal content of nerve‐evoked endplate currents and on the kinetic parameters of quantal release (minimal synaptic delay, value of main mode of synaptic delay histogram, and variability of synaptic delay) were studied at the mouse neuromuscular synapse. At low calcium ion concentrations (0.2–0.6 mmol/L), evoked signals with long synaptic delays (several times longer than the value of main mode) were observed. Their number decreased substantially when [Ca2+]o was increased (i.e. the release of transmitter became more synchronous). By contrast, the early phase of secretion, characterized by minimal synaptic delay and accounting for the main peak of the synaptic delay histogram, did not change significantly with increasing [Ca2+]o. Hence, extracellular calcium affected mainly the late, ‘asynchronous’, portion of phasic release. The average quantal content grew exponentially from 0.09 ± 0.01 to 1.04 ± 0.07 with the increase in [Ca2+]o without reaching saturation. Similar results were obtained when calcium was replaced by strontium, but the asynchronous portion of phasic release was more pronounced and higher strontium concentrations (to 1.2–1.4 mmol/L) were required to abolish responses with long delays. Treatment of preparations with 1,2‐bis(2‐aminophenoxy)ethane‐N,N,N′,N′‐tetraacetic acid tetrakis acetoxymethyl ester (BAPTA‐AM) (25 µmol/L), but not with ethylene glycol‐bis(2‐aminoethylether)‐N,N,N′,N′‐tetraacetic acid acetoxymethyl ester (EGTA‐AM) (25 µmol/L), abolished the responses with long delays. The dependence of quantal content and synchrony of quantal release on calcium and strontium concentrations have quite different slopes, suggesting that they are governed by different mechanisms.
THIS ARTICLE HAS BEEN RETRACTED: Functional nerve growth factor and trkA autocrine/paracrine circuits in adult rat cortex are revealed by episodic ethanol exposure and withdrawal
Authors: Bruns Marla B. , Miller Michael W.
Published: December 2006

The hypothesis tested is that cortical neurotrophins communicate through an inducible autocrine/paracrine mechanism. As ethanol (Et) can induce cortical nerve growth factor (NGF) expression, adult rats were challenged with Et on three consecutive days per week for 6 weeks. The focus of the study was layer V, the chief repository of receptor‐expressing neuronal cell bodies. Brains were collected immediately after the sixth Et exposure or 72 h later [i.e., following withdrawal (WD)]. Double‐label in situ hybridization–immunohistochemistry studies showed that many neuronal somata co‐expressed NGF mRNA with NGF, trkA, or phosphorylated trk (p‐trk), essential components of an inducible autocrine system. The frequencies of co‐labeling were affected by neither Et nor WD. On the contrary, Et increased the number of NGF mRNA‐expressing neurons and the amount of NGF mRNA expressed per cell. Et also increased total cortical concentration of NGF protein, the number of layer V neurons expressing trkA transcript, the amount of trkA mRNA expressed per neuron, and trkA phosphorylation. Following WD, the frequency of NGF‐mRNA‐expressing cells increased, although transcript and protein content fell. WD induced an increase in trkA mRNA and protein expression, however, p‐trk expression was unaffected. Thus, Et treatment reveals that layer V has inducible autocrine/paracrine and anterograde neurotrophin systems. WD unveils the dynamism and recruitability of these systems.
Expression of annexin A2 in GABAergic interneurons in the normal rat brain
Authors: Zhao Wei‐Qin , Lu Bai
Published: December 2006

Expression of the Ca2+‐dependent phospholipids binding protein annexin A2 (ANX2) in the brain is thought to be largely associated with brain pathological conditions such as tumor, inflammation, and neurodegeneration. The recent findings that ANX2 heterotetramer is involved in learning and neuronal activities necessitates a systematic investigation of the physiological expression of ANX2 in the brain. With combination of in situ hybridization and immunohistochemistry, ANX2 mRNA and protein were specifically detected in a group of GABAergic interneurons throughout the brain. Although ANX2 was absent from the interior of pyramidal neurons, it was found on the membrane and seemly the extracellular space of those neurons, where they closely co‐localized with glutamate decarboxylase terminals. In cultured developing neurons, ANX2 was present at high concentrations in the growth cones co‐distributing with several growth‐associated proteins such as growth associated protein 43 (GAP43), turned on after division/Ulip/CRMP (TUC‐4), tubulin, and tissue‐plasminogen activator. It then became predominantly distributed on the membrane and mostly in axonal branches as neurons grew and extended synaptic networks. ANX2 was also secreted from cultured neurons, in a membrane‐bound form that was Ca2+‐dependent, which was significantly increased by neuronal depolarization. These results may have implications in the function and regulatory mechanism of ANX2 in the normal brain.
Truncated tyrosine kinase B brain‐derived neurotrophic factor receptor directs cortical neural stem cells to a glial cell fate by a novel signaling mechanism
Authors: Cheng Aiwu , Coksaygan Turhan , Tang Hongyan , Khatri Rina , Balice‐Gordon Rita J. , Rao Mahendra S. , Mattson Mark P.
Published: December 2006

During development of the mammalian cerebral cortex neural stem cells (NSC) first generate neurons and subsequently produce glial cells. The mechanism(s) responsible for this developmental shift from neurogenesis to gliogenesis is unknown. Brain‐derived neurotrophic factor (BDNF) is believed to play important roles in the development of the mammalian cerebral cortex; it enhances neurogenesis and promotes the differentiation and survival of newly generated neurons. Here, we provide evidence that a truncated form of the BDNF receptor tyrosine kinase B (trkB‐t) plays a pivotal role in directing embryonic mouse cortical NSC to a glial cell fate. Expression of trkB‐t promotes differentiation of NSC toward astrocytes while inhibiting neurogenesis both in cell culture andin vivo. The mechanism by which trkB‐t induces astrocyte genesis is not simply the result of inhibition of full‐length receptor with intrinsic tyrosine kinase activity signaling. Instead, binding of BDNF to trkB‐t activates a signaling pathway (involving a G‐protein and protein kinase C) that induced NSC to become glial progenitors and astrocytes. Thus, the increased expression of trkB‐t in the embryonic cerebral cortex that occurs coincident with astrocyte production plays a pivotal role in the developmental transition from neurogenesis to gliogenesis. Our findings suggest a mechanism by which a single factor (BDNF) regulates the production of the two major cell types in the mammalian cerebral cortex.
Identification of microsatellite markers in Plasmodium mexicanum, a lizard malaria parasite that infects nucleated erythrocytes
Authors: SCHALL JOS J. , VARDO ANNE M.
Published: December 2006

Reptile and bird hosts of malaria parasites (Plasmodium) have nucleated erythrocytes. Infected blood thus contains a mix of abundant host and scant parasite DNA which has prevented identification of Plasmodium microsatellites. We developed a protocol for isolation of microsatellite markers for Plasmodium mexicanum, a parasite of lizards. The ATT repeat was common in the genome of P. mexicanum, but most (87%) of these repeats were exceptionally long (50–206 + repeats). Seven microsatellite markers with polymerase chain reaction primers are described. The protocol should allow discovery of microsatellites of malaria parasites (with AT‐rich genomes) infecting bird and reptile hosts.
Treatment of cellulite with a bipolar radiofrequency, infrared heat, and pulsatile suction device: a pilot study
Authors: Wanitphakdeedecha Rungsima , Manuskiatti Woraphong
Published: December 2006

Background  Very few therapeutic options have proven effective in the treatment of cellulite.

Aims  To evaluate the effectiveness and adverse effects of a bipolar radiofrequency (RF), infrared (IR) heat and pulsatile suction device for the treatment of cellulite.

Methods  Twelve subjects were treated with the RF‐light‐based device. All subjects were treated twice weekly for a total number of eight to nine treatments. Subjects were evaluated using standardized photographs, and measurements of body weight and circumference of treatment sites at baseline, immediately after the last treatment, and four weeks and one year after the last treatment. Clinical improvement scores of comparable photographs using a quartile grading scale (0 = <25%, 1 = 25–50%, 2 = 51–75%, 3 = >75% improvement) were judged independently by two non‐treating dermatologists after the series of treatment.

Results  The average body weights at baseline, immediately after the last treatment, and four weeks and one year after the complete treatment were 56.30, 56.05, 56.23, and 56.53 kg, respectively. The average circumferential reductions of the abdomen and thigh at the last treatment visit were 5.17 ± 1.04 cm (6.32%± 1.82%) and 3.50 ± 2.16 cm (6.23 ± 3.58%), respectively. At four weeks after the last treatment, the average circumferential reductions of the abdomen and thigh were sustained at 3.17 ± 2.75 cm (4.04%± 3.69%) and 3.50 ± 2.04 cm (6.26%± 3.52%), respectively. At one year follow‐up visit, the average circumferential reductions of the abdomen and thigh were maintained at 3.83 ± 0.76 cm (4.64%± 1.15%) and 3.13 ± 3.54 (5.50%± 6.12%), respectively. Average clinical improvement scores of the abdomen and thigh after the series of treatments were 0.75 (corresponding to ~25% improvement), and 1.75 (corresponding to ~50% improvement), respectively.

Conclusions

A bipolar RF, IR heat and pulsatile suction device provides a beneficial effect on reduction of abdomen and thigh circumference, and smoothening of the cellulite.
The neuropeptide/mast cell secretagogue substance P is expressed in cutaneous melanocytic lesions
Authors: Khare Vivek K. , Albino Anthony P. , Reed Jon A.
Published: December 2006

Substance P (SP) is a neuropeptide found in both the central and peripheral nervous system. In the skin, SP‐containing neurons stimulate the release of histamine from connective tissue mast cells (MC). SP also can potentiate neoangiogenesis and induce dermal fibrosis. MC‐derived histamine has potent vasoactive effects, is angiogenic, and promotes tissue fibroplasia. In addition to histamine, MC contain many other angiogenic factors and a variety of cytokines, growth factors, and proteolytic enzymes implicated in tissue remodeling, and normal as well as tumor‐associated neoangiogenesis. Many MC‐derived factors, including histamine, can enhance melanoma cell growth directly. MC often concentrate around cutaneous melanomas which also frequently are associated with angiogenesis and peritumoral fibrosis. The precise mediators of these responses have not been well defined. We evaluated by immunohistochemistry cutaneous lesions representing stages of progression of malignant melanoma and its precursor lesions for the expression of SP. SP was expressed in 17/25 (68%) primary invasive malignant melanomas, 2/5 (40%) metastatic melanomas, 6/10 (60%) melanomas in situ, 7/12 (58%) atypical (dysplastic) nevi, and 4/10 (40%) spindle and epithelioid cell (Spitz) nevi, but was not detected in any (0/11, 0%) acquired benign melanocytic nevi (p<0.05). Invasive melanomas were immunolabeled in both the intraepidermal and the dermal components of the lesions. For those atypical and Spitz nevi which expressed SP, most of the immunoreactive melanocytes were located at the dermal‐epidermal junction overlying areas of papillary dermal fibrosis. The results show differential expression of SP among cutaneous melanocytic lesions and suggest that the expression of this neuropeptide together with other factors may contribute to some of the host responses associated with these lesions.
Leiomyomatous nodules and bundles of vascular origin in the fibrosarcomatous variant of dermatofibrosarcoma protuberans
Authors: Sanz‐Trelles Andrés , Ayala‐Carbonero Ana , Rodrigo‐Fernández Isabel , Weil‐Lara Bernardo
Published: December 2006

We report 5 cases of the fibrosarcomatous variant of dermatofibrosarcoma protuberans, 4 of which presented a morphologic change of intraneoplastic blood vessels not previously recognized. This change consisted of focal proliferation of smooth muscle cells, resulting in hypertrophy, generally eccentric, of vascular walls with reduction and collapsing of vascular lumina. In 3 cases the proliferation was so intense it formed leiomyomatous nodules and bundles. This proliferation may originate in the smooth muscle cells of the vessel walls either by means of a hyper‐plastic mechanism or in the pericytes via a line of differentiation leading to mature smooth muscle cells. In either case, we believe that it concerns a reactive process of the vessel walls very probably induced by adjacent neoplastic cells. The cases recently reported by Calonje and Fletcher as “myoid differentiation” of neoplastic cells in dermatofibrosarcoma protuberans (DFSP) may well be an expression of the same phenomenon, and therefore the presence of leiomyomatous areas in this tumor should not be used to support the theory of a fibroblastic/myofibroblastic line of differentiation for DFSP.
Papillary eccrine adenoma: Immunohistochemicai study and literature review
Authors: Mizuoka H. , Senzaki H. , Shikata N. , Uemura Y. , Tsubura A.
Published: December 2006

A case of papillary eccrine adenoma on the right forearm of a 78‐year‐old Japanese woman is reported. The tumor was 1.3 cm in diameter, occupying the whole thickness of the dermis. Histologically, the tumor was composed of dilated tubules of various sizes with intraluminal papillary projections, and was surrounded by a fibrous stroma. An immunohistochemical study revealed that the proliferating tubules were composed of a single outermost layer of α‐smooth muscle actin‐and keratin 14‐positive myoepithelial cells, and keratin 8‐positive inner cells. This antigen expression pattern was comparable to that of the normal eccrine secretory coil, which indicates that the tumor differentiated toward the secretory coil of an eccrine sweat gland.
Nodular post‐kala‐azar dermal leishmaniasis: a distinct histopathological entity
Authors: Singh Navjeevan , Ramesh Venkatesa , Arora Vinod K. , Bhatia Arati , Kubba Asha , Ramam M.
Published: December 2006

Post‐kala‐azar dermal leishmaniasis (PKDL) is an infrequently occurring sequel to treated visceral leishmaniasis. Diagnosis, particularly in non‐endemic areas, is difficult because the clinical appearances may be subtle and simulate lepromatous leprosy. The histopathology of the condition has been a neglected subject. Nodular lesions constitute one of the large variety of lesions that can be seen in PKDL. This paper describes the histopathology of such lesions in 26 patients seen over a period of approximately 8 years in a non‐endemic setting. All the biopsies had strikingly similar light microscopic features with characteristic findings: a dense lymphohistiocytic infiltrate beneath an atrophic epidermis, pronounced follicular plugging, vascular hyalinization and collagen changes and negative Fite stain. Tbese allow a definite diagnosis of PKDL even in the absence of demonstrable Leishman‐Donovan (L‐D) bodies.
Cutaneous infiltrate of chronic lymphocytic leukemia and relationship to primary cutaneous epithelial neoplasms
Authors: Smoller Bruce R. , Warnke Roger A.
Published: December 2006

Chronic lymphocytic leukemia involves the skin in a small percentage of patients and may portend an ominous prognosis in some patients. We report a series of eight biopsies from seven different patients in which the cutaneous leukemic infiltrate was confined exclusively to the region immediately surrounding primary epithelial neoplasms including squamous cell carcinoma (6), basal cell carcinoma (1) and actinic keratosis (1). The malignant lymphocytes appear to constitute a host response to these neoplasms and do not appear to suggest a rapid downhill course for these patients. These observations serve to 1) suggest a new pattern of cutaneous involvement by leukemic cells and 2) offer some insights into potential cellular trafficking patterns of these neoplastic cells.
Signet‐ring squamous cell carcinoma: a case report
Authors: McKinley E. , Valles R. , Bang R. , Bocklage T.
Published: December 2006

A 50‐year‐old Hispanic man presented to the dermatology clinic with a 0.6‐cm eroded, erythematous, scaly plaque on the left side of his neck. On shave biopsy, the lesion was composed of intra‐epidermal and invasive dermal cells characterized by a signet‐ring appearance. One area suggestive of topical squamous cell carcinoma prompted the inclusion of that entity in the differential diagnosis. Mucicarmine stains were negative, while the extra‐vacuolar cytoplasm focally reacted with periodic acid‐Schiff staining, the positive reaction for which was abolished by diastase, consistent with glycogen. Malignant cells expressed keratins by reacting to antibodies, Mak6, AE1/AE3, Ker 903, and CAM5.2. Additionally, weak reactivity occurred with antibodies to CEA and EMA. Tumor cells did not express S‐100, HM‐B45, Leu M1, or actin. By ultrastructural examination, the large vacuoles corresponded to markedly dilated endoplasmic reticulum. A diagnosis of signetring squamous cell carcinoma, a rare form of cutaneous squamous cell carcinoma which has been described in only one case report in the last 10 years, was made. Immunohistochemical staining provided information useful in differentiating this lesion from other clear cell and signet‐ring cell tumors which involve the skin.
Tyrosinase immunoreactivity in formalin‐fixed, paraffin‐embedded primary and metastatic melanoma: frequency and distribution
Authors: Hofbauer Günther F. L. , Kamarashev Jivko , Geertsen Ralf , Böni Roland , Dummer Reinhard
Published: December 2006

Monoclonal antibody T311 specifically detects tyrosinase protein expression. Tyrosinase‐derived peptides are recognized by CD8+ T‐celis and applied in immunotherapy. We examined formalin‐fixed paraffin‐embedded tissue of 50 melanoma (primary n=31, metastatic n=19) and 41 control cases (junctional, dermal, compound, Spitz, Reed, balloon‐cell nevi) by immunochemistry using the alkaline phosphatase‐anti‐alkaline phosphatase method after antigen retrieval. Staining with mAb T311 showed a sensitivity of 94% for melanoma with a very high specificity for melanocytic cells. Immunopositivity (94% of melanomas overall) correlated inversely with clinical stage: clinical stage I and stage II showed 100%, stage III and stage IV 86% immunoreactivity each. Staining changed from an exclusively homogeneous pattern in early stages to a more heterogeneous pattern in later stages. Melanocytic control tissue like nevi of different subtypes all showed weak to moderate, homogeneous immunoreactivity with polarity towards the epidermis. RT‐PCR ELISA analysis of short‐term melanoma cell cultures displayed mRNA expression in only half of the originally immunopositive tumors only, suggesting rapid mRNA expression loss in culture. mAb T311 allows detection of melanoma‐associated tyrosinase protein expression and thus profiling of melanomas using routine archival tissue suited for immunotherapy approaches involving tyrosinase derived epitopes.
Tongue pain: burning mouth syndrome vs Candida‐ associated lesion
Authors: Terai H , Shimahara M
Published: December 2006

Objective:  We investigated patients with tongue pain to examine whether the differential diagnosis of burning mouth syndrome and Candida‐associated lesion was possible.

Patients and methods:  Sixty patients with tongue pain were divided into three groups according to the intensity of pain at rest and that when eating using the visual analogue scale: Group A: Functional pain group. Group B: Non‐functional pain group. Group C: Mixed pain group. Antifungal treatment was scheduled for patients suspected clinically, mycologically or cytologically as having candidal infection.

Results:  The results of the culture test and direct examination indicated that group A was different from others by its high positivity for Candida, a good response to the antifungal treatment was obtained. On the other hand, antifungal treatment was not useful in group B, and the low possibility of Candida infection in the direct examination supported the result in this group. In group C, the positivity of Candida and the effect of the antifungal treatment were between groups A and B.

Conclusion:  These results may suggest that tongue pain in group A is Candida‐associated, that in group B is burning mouth syndrome‐induced and that of group C is mixed conditions.
EFFECTS OF PELVIC POSITIONING AND SIMULATED DORSAL ACETABULAR RIM REMODELING ON THE RADIOGRAPHIC SHAPE OF THE DORSAL ACETABULAR EDGE
Authors: THOMPSON RANDALL , ROE SIMON C. , ROBERTSON IAN D.
Published: December 2006

A radiographic study was conducted to evaluate the effect of pelvic rotation and of simulated dorsal acetabular rim (DAR) remodeling on the radiographic appearance of the dorsal acetabular edge (DAE). The DAE is the line connecting the cranial and caudal rims of the acetabulum when viewing a pelvic radiograph made with the dog in the ventrodorsal position with the hind limbs extended. In this study, it was hypothesized that the DAE would change with pelvic rotation and simulated DAR damage. Ventrodorsal radiographs of eight canine pelves were made at 0°, 5°, and 10° of left and right pelvic rotation over its longitudinal axis. These radiographs were repeated following removal of 2, 4, and then 6 mm of bone from the right DAR of each pelvis. The ratio of acetabular width to maximum depth of the DAE was calculated. The area between the DAE and a straight line connecting the cranial and caudal acetabular rims was measured digitally. The DAE depth and area changed with pelvic rotation, and with increasing simulated DAR damage. A linear relationship between the obturator foramina width ratio and pelvic rotation allowed estimation of the degree and direction of pelvic rotation. Equations were developed from the data to assist with the estimation of the amount of DAR remodeling on a clinical radiograph.
FAT NECROSIS SIMULATING RECURRENT NEOPLASIA FOLLOWING EXTERNAL BEAM RADIOTHERAPY IN A DOG
Authors: LOOPER JAYME S.
Published: December 2006

A 4.5‐year‐old neutered male dog was diagnosed with incompletely excised well‐differentiated lymphangiosarcoma in the right inguinal subcutaneous region. The mass had metastasized to the right hypogastric and medial iliac lymph nodes. Surgery followed by definitive radiation therapy was administered to the primary site and the sites of metastasis. The dog had a complete response to radiotherapy, and minimal acute side effects. Doxorubicin was administered after radiotherapy. Approximately 4 months following radiation therapy, the dog developed a mass, presumed recurrent tumor, in the original site. In a biopsy only steatitis and fibrosis were found. The mass continued to grow and conservative surgical excision was elected. Histopathologically the diagnosis was fat necrosis and steatitis, with a microscopic focus of lymphangiosarcoma. Fat necrosis is an uncommon sequelum to breast irradiation in people and also appears to be rare in animals. Fat necrosis should be considered as a differential diagnosis when recurrent tumor is suspected in a previously irradiated subcutaneous site in a dog.
Curcumin and Kolaviron Ameliorate Di‐n‐Butylphthalate‐Induced Testicular Damage in Rats
Authors: Farombi Ebenezer Olatunde , Abarikwu Sunday O. , Adedara Isaac A. , Oyeyemi Matthew O.
Published: December 2006

Abstract:  The present study was carried out to evaluate the ameliorative effects of kolaviron (a biflavonoid from the seeds of Garcinia kola) and curcumin (from the rhizome, Curcuma longa L.) on the di‐n‐butylphthalate (DBP)‐induced testicular damage in rats. Administration of DBP to rats at a dose of 2 g/kg for 9 days significantly decreased the relative testicular weights compared to the controls, while the weights of other organs remained unaffected. Curcumin or kolaviron did not affect all the organ weights of the animals. While only DBP treatment significantly increased the testicular malondialdehyde level and gamma‐glutamyl transferase activity (γ‐GT), it markedly decreased glutathione level, the testicular catalase, glucose‐6‐phosphate dehydrogenase, superoxide dismutase, sperm γ‐GT activities and serum testosterone level compared to the control group. Data on cauda epididymal sperm count and live/dead ratio were not significantly affected in the DBP‐treated rats. Alone, DBP treatment resulted in a 66% decrease in spermatozoa motility and a 77% increase in abnormal spermatozoa in comparison to control. DBP‐treated rats showed marked degeneration of the seminiferous tubules with necrosis and defoliation of spermatocytes. The DBP‐induced injuries in biochemical, spermatological parameters and histological structure of testis were recovered by treatment with kolaviron or curcumin. The pattern in the behaviour of these compounds might be correlated with their structural variations. Our results indicate that kolaviron and curcumin protect against testicular oxidative damage induced by DBP. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties and as such may prove useful in combating phthalate‐induced reproductive toxicity.
Who’s Skipping School: Characteristics of Truants in 8th and 10th Grade
Authors: Henry Kimberly L.
Published: December 2006

Background:  Truancy is a serious concern that affects most school districts in the United States; however, we do not have accurate estimates of the prevalence of truancy due to inconsistent tracking and reporting practices of schools. As a result, our best current estimates of the national state of truancy may be from self‐reported data. In this article, the first objective is to present the prevalence of self‐reported recent truancy (ie, truancy within the past 4 weeks) among 8th‐ and 10th‐grade students. The second objective is to explore associations between recent truant behavior, demographic and family characteristics, school‐related risk factors, and drug use.

Methods:  The 2003 wave of the Monitoring the Future data was analyzed. Logistic regression analysis was used to assess the association between many potential predictors and the probability of recent truancy.

Results:  Nearly, 11% of 8th graders and over 16% of 10th graders reported recent truancy. Among the most salient predictors of recent truancy were parental education, having large amounts of unsupervised time after school, school disengagement variables (eg, poor grades and low educational aspirations), and drug use.

Conclusions:  Truancy is a common behavior among adolescents and can have potentially deleterious effects. This paper offers insight into the types of students who may be prone to skipping school and suggests potential target audiences for truancy prevention initiatives.
Fractures in New Zealand Elementary School Settings
Authors: Rubie‐Davies Christine M. , Townsend Michael A. R.
Published: December 2006

Background:  There is a need for greater international understanding of student safety in schools. This New Zealand study investigated the causes and school location of fractures sustained by students attending elementary school, with special emphasis on the types of fractures sustained following falls from playground equipment of various heights.

Methods:  Over a 1‐year period, 76 participating schools (with a combined roll of over 25,000 students) completed a questionnaire about the nature and circumstances of student fractures sustained during regular school hours.

Results:  Some 118 students sustained a total of 131 fractures. Injuries from playground equipment were no more frequent than those from general activities at school, and most were sustained in falls from heights less than 59 inches. Most fractures were to the upper limbs. Fractures were found to vary by gender and school size.

Conclusions:  The results are discussed in terms of the conditions and policies present in local schools, and the tension that exists in maintaining safety while offering appropriate challenges to students. Improvements in school safety may be more likely to result from a greater focus on the way that students interact at school, rather than on modifications to playground equipment.
Non‐human primate fetal kidney transcriptome analysis indicates mammalian target of rapamycin (mTOR) is a central nutrient‐responsive pathway
Authors: Nijland Mark J. , Schlabritz‐Loutsevitch Natalia E. , Hubbard Gene B. , Nathanielsz Peter W. , Cox Laura A.
Published: December 2006

Developmental programming is defined as the process by which gene–environment interaction in the developing organism leads to permanent changes in phenotype and function. Numerous reports of maternal nutrient restriction during pregnancy demonstrate altered renal development. Typically this alteration manifests as a reduction in the total number of glomeruli in the mature kidney of the offspring, and suggests that predisposition to develop chronic renal disease may include an in utero origin. In a previous study, we defined the transcriptome in the kidney from fetuses of control (CON, fed ad libitum) and nutrient‐restricted (NR, fed 70% of CON starting at 0.16 gestation (G)) pregnancies at half‐way through gestation (0.5G), and established transcriptome and morphological changes in NR kidneys compared to CON. One goal of the present study was to use transcriptome data from fetal kidneys of CON and NR mothers at 0.5G with histological data to identify the molecular mechanisms that may regulate renal development. A second goal was to identify mechanisms by which NR elicits its affect on fetal baboon kidney. We have used an end‐of‐pathway gene expression analysis to prioritize and identify key pathways regulating the 0.5G kidney phenotype in response NR. From these data we have determined that the mammalian target of rapamycin (mTOR) signalling pathway is central to this phenotype.
Evidence for association of GABAB receptors with Kir3 channels and regulators of G protein signalling (RGS4) proteins
Authors: Fowler Catherine E. , Aryal Prafulla , Suen Ka Fai , Slesinger Paul A.
Published: December 2006

Many neurotransmitters and hormones signal by stimulating G protein‐coupled neurotransmitter receptors (GPCRs), which activate G proteins and their downstream effectors. Whether these signalling proteins diffuse freely within the plasma membrane is not well understood. Recent studies have suggested that direct protein–protein interactions exist between GPCRs, G proteins and G protein‐gated inwardly rectifying potassium (GIRK or Kir3) channels. Here, we used fluorescence resonance energy transfer (FRET) combined with total internal reflection fluorescence microscopy to investigate whether proteins within this signalling pathway move within 100 Å of each other in the plasma membrane of living cells. GABAB R1 and R2 receptors, Kir3 channels, Gαo subunits and regulators of G protein signalling (RGS4) proteins were each fused to cyan fluorescent protein (CFP) or yellow fluorescent protein (YFP) and first assessed for functional expression in HEK293 cells. The presence of the fluorophore did not significantly alter the signalling properties of these proteins. Possible FRET was then investigated for different protein pair combinations. As a positive control, FRET was measured between tagged GABAB R1 and R2 subunits (∼12% FRET), which are known to form heterodimers. We measured significant FRET between tagged RGS4 and GABAB R1 or R2 subunits (∼13% FRET), and between Gαo and GABAB R1 or R2 subunits (∼10% FRET). Surprisingly, FRET also occurred between tagged Kir3.2a/Kir3.4 channels and GABAB R1 or R2 subunits (∼10% FRET). FRET was not detected between Kir3.2a and RGS4 nor between Kir3.2a and Gαo. These data are discussed in terms of a model in which GABAB receptors, G proteins, RGS4 proteins and Kir3 channels are closely associated in a signalling complex.
Tonic activation of NMDA receptors by ambient glutamate of non‐synaptic origin in the rat hippocampus
Authors: Meur Karim Le , Galante Micaela , Angulo María Cecilia , Audinat Etienne
Published: December 2006

In several neuronal types of the CNS, glutamate and GABA receptors mediate a persistent current which reflects the presence of a low concentration of transmitters in the extracellular space. Here, we further characterize the tonic current mediated by ambient glutamate in rat hippocampal slices. A tonic current of small amplitude (53.99 ± 6.48 pA at +40 mV) with the voltage dependency and the pharmacology of NMDA receptors (NMDARs) was detected in virtually all pyramidal cells of the CA1 and subiculum areas. Manipulations aiming at increasing d‐serine or glycine extracellular concentrations failed to modify this current indicating that the glycine binding sites of the NMDARs mediating the tonic current were saturated. In contrast, non‐transportable inhibitors of glutamate transporters increased the amplitude of this tonic current, indicating that the extracellular concentration of glutamate primarily regulates its magnitude. Neither AMPA/kainate receptors nor metabotropic glutamate receptors contributed significantly to this tonic excitation of pyramidal neurons. In the presence of glutamate transporter inhibitors, however, a significant proportion of the tonic conductance was mediated by AMPA receptors. The tonic current was unaffected when inhibiting vesicular release of transmitters from neurons but was increased upon inhibition of the enzyme converting glutamate in glutamine in glial cells. These observations indicate that ambient glutamate is mainly of glial origin. Finally, experiments with the use‐dependent antagonist MK801 indicated that NMDARs mediating the tonic conductance are probably extra‐synaptic NMDARs.
Reversing the hydrogen silsesquioxane image by silicon nitride and silicon oxide chemical mechanical polishing
Authors: van Delft F. C. M. J. M. , van der Kruis F. J. H. , van Eerd P. P. J. , van Esch H. A. , van de Laar H. W. J. J.
Published: December 2006

Patterns, e-beam written in hydrogen silsesquioxane (HSQ), have been reversed in tone by chemical mechanical polishing of silicon nitride deposited on top of these HSQ patterns. First, high-resolution patterns have been written in an 80nm thick HSQ layer on a 6in. silicon wafer. After development, 200nm thick plasma enhanced chemical vapor deposited silicon nitride has been deposited at 300°C on top of these patterns. Next, the silicon nitride has been Syton polished down to 50nm thickness. Finally, the HSQ has been removed wet chemically from in between the nitride features using buffered oxide etch (7:1). Features of 50nm wide have been resolved, but even smaller isolated spaces are feasible. The same method has been tested with silicon oxide obtained from boron doped tetraethyl orthosilicate. Although the wet-chemical removal of HSQ is less selective in this case, still 50nm wide features have been resolved in silicon oxide this way.
Study of diffusion barriers for Au metal on liquid phase oxidized GaAs
Authors: Sze Po-Wen , Huang Jian-Jiun , Chou Dei-Wei , Wang Yeong-Her
Published: December 2006

TiW, TiN, Pd, and Mo as the diffusion barriers (DBs) in Au/DB/GaAs native oxide multilayer structures are investigated. The GaAs native oxides are prepared by liquid phase oxidation, and the results indicate that TiW and Mo films can effectively block Au diffusion at temperatures of up to 550°C for 30min. However, TiN and Pd films can effectively block Au diffusion only at 450°C for 30min. The failure of TiN and Pd appears related to the embedded oxygen in the barrier layers which cause the interdiffusion between Au and the barrier films. In comparison, TiW and Mo show better blocking properties that prevent Au from diffusing into oxide films. They also act as a diffusion barrier even at temperatures above 550°C.
Magnetization losses in submicrometer CoFeB dots etched in a high ion density Cl2-based plasma
Authors: Fabrie C. G. C. H. M. , Kohlhepp J. T. , Swagten H. J. M. , Koopmans B. , Andriesse M. S. P. , van der Drift E.
Published: December 2006

Faceting of the etch masks and chlorinated etch residues can reduce the magnetization of patterning magnetic materials substantially, and therefore, constitutes a considerable concern. To get more insight into the magnetization losses, CoFeB dots were etched in a high ion density Cl2-based plasma with a width ranging from 0.3to6.4μm. The magnetic properties of the CoFeB dots were measured by magnetometry. Submicrometer CoFeB dots showed significant magnetization reductions despite H2O rinsing. Scanning electron microscopy (SEM) studies revealed that etching in a Cl2-based plasma caused faceting of the masks, leading to sloped sidewalls. SEM pictures were used to determine the geometric volume, which was compared to the effective magnetic volume resulting from the magnetometry measurements. The SEM data are in good agreement with the magnetometry data, and a chloride penetration depth of only a few nanometers could be derived, indicating that the postetch rinsing is sufficient to prevent considerable corrosion of the CoFeB dots.
Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe∕Si
Authors: Isaacson David M. , Dohrman Carl L. , Fitzgerald Eugene A.
Published: December 2006

The authors report the sudden rise in threading dislocation density in Ge-rich relaxed graded SiGe layers grown at higher growth temperatures (T>550°C). They attribute this rise in threading dislocation density in relaxed Ge to dislocation nucleation. This observation is contrary to conventional graded buffers in Si-rich material, where higher growth temperatures result in reduced threading dislocation densities (TDDs). Additionally, a coupling effect between the effective strain during graded buffer growth and the growth rate was observed, as evidenced by increased TDD values at reduced growth rates. They conclude that reduced growth rates allow more time for the surface to evolve (i.e., roughen) during growth, thereby trapping mobile dislocations and necessitating the nucleation of additional dislocations to continue relaxing the structure.
Interconnecting single nano-objects on surfaces for transport experiments
Authors: Della Torre A. , Pompa P. P. , del Mercato L. L. , Cingolani R. , Rinaldi R. , Shiv Shankar S. , Sastry M.
Published: December 2006

The authors report a highly controlled approach, based on electron-beam lithography, to interconnect individual nano-objects for transport experiments. The process is based on a three-step procedure, consisting of fabrication of four alignment markers, localization of the nano-object after its immobilization onto functionalized surfaces, and interconnection of the single nanostructure by patterning two nanoelectrodes on its sides. The approach is highly reproducible and widely applicable and allows an alignment accuracy of 15–20nm. Here they demonstrate the reliability of such technique by using a thin triangular gold nanoprism as the active element and show the I-V characteristics of the single nanostructure.
Efficient fabrication and characterization of cobalt nanoparticles embedded in metal∕oxide∕semiconductor structures for the application of nonvolatile memory
Authors: Yang Jung Yup , Yoon Kap Soo , Choi Won Joon , Do Young Ho , Kim Ju Hyung , Kim Chae Ok , Hong Jin Pyo
Published: December 2006

Metal-oxide-semiconductor (MOS) capacitors with Co nanoparticles (Co NPs) were successfully fabricated by utilizing an external laser irradiation method for the application of nonvolatile memory. Experimental images of cross-sectional transmission electron microscopy showed that the Co NPs of 5nm in diameter were clearly embedded in SiO2 layer. Capacitance-voltage measurements of Pt∕SiO2∕Co NPs∕SiO2 on p-type Si (100) substrate certainly exhibited typical MOS behavior with a flatband voltage shift of 1.1V. In addition, the charge retention characteristics of MOS capacitors with the Co NP were investigated using capacitance-time measurements. The present results indicate that their unique laser process gives rise to a possible promise for the efficient formation or insertion of metal NPs inside the MOS structures.
Immersion patterning down to 27nm half pitch
Authors: Bloomstein T. M. , Fedynyshyn T. H. , Pottebaum I. , Marchant M. F. , Deneault S. J. , Rothschild M.
Published: December 2006

Liquid immersion interference lithography at 157nm has been used to print gratings of 27nm half pitch with a fluorine-doped fused silica prism having index of 1.66. In order to achieve these dimensions, new immersion fluids have been designed and synthesized. These are partially fluorinated organosiloxanes with indexes up to 1.5. Their absorbance is on the order of 0.4∕μm (base 10), enabling the use of liquid films with micron-size thickness. To utilize these semiabsorptive fluids, an immersion interference printer has been designed, built, and implemented for handling micron-scale liquid layers.
Sub- 100-nm lithography with miniature electron beam columns
Authors: Muray L. P. , Silver C. S. , Spallas J. P.
Published: December 2006

Miniature low-voltage electron beam columns are well suited for low cost imaging and high throughput direct-write lithography applications. Previous generations of miniature columns have demonstrated high-resolution imaging and proof-of-concept lithography. However, those columns suffered from difficult fabrication techniques and costly assembly, making them impractical for broad application. A new type of miniature electron beam column has been developed with the goal of manufacturability using bonded stacks of batch fabricated silicon lenses and glass insulators. Bulk micromachining and integrated chip fabrication techniques facilitate the fabrication of columns with precise aperture-to-aperture alignment and high aperture circularity. The lens stacks are bonded to a multilayer ceramic package with embedded interconnects. This approach enables a small package that can include buried internal and external passive and active devices, ground planes, and controlled impedance-matched lines. The package is fully scalable for continued miniaturization, and can be easily designed to accommodate 1×4 or larger modules of individually correctable columns for arrayed operation. This article presents the first lithography results with these miniature columns over a beam energy range of 0.5–2keV. Patterns were written into ∼45nm ZEP-520A resist using a raster-scan writing strategy. A nominal dose of 7μC∕cm2 yielded 90nm isolated and 180nm line-space patterns. High-resolution images resolved <35nm features.
Predicted effect of shot noise on contact hole dimension in e-beam lithography
Authors: Kruit P. , Steenbrink S. , Wieland M.
Published: December 2006

The requirements on dimensional control of contact holes scale with the technology node and are reaching values of only a few nanometers. The allowed 3σ variation of the diameter is typically 10%. In traditional optical lithography, cross section variations occur mainly on a global scale as a result of slowly varying image or process parameters. For electron beam lithography and extreme ultraviolet (EUV) lithography, local variations need more attention. The authors have developed a model for the critical dimension (CD) variations resulting from shot noise and checked the results with Monte Carlo simulations. The model predicts that the necessary number of particles to write a contact is independent of the contact diameter, when both the requirements, the resolution, and resist’s acid diffusion length scale with the size of the contacts. The minimum number of particles required under ideal circumstances is about 500 per contact, but under more realistic circumstances, e.g., for electron beam lithography at low voltages, a typical number of electrons per contact is 3900. This means that contact holes at the “32nm node” (45nm diameter at 90nm pitch with 3σ of 4.5nm) require a dose of about 30μC∕cm2 and at the “22nm node” about 60μC∕cm2. If the molecular size of the resist molecules contributes to a size variance, or if high energy electrons or EUV photons are used, the required dose may be substantially higher.