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1.
Rev Sci Instrum ; 90(2): 026102, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30831743

ABSTRACT

The measurement of surface photovoltage (SPV) transients over 12 orders of magnitude in time was recently demonstrated [Rev. Sci. Instrum. 88, 053904 (2017)]. In dedicated experiments, however, a high-impedance buffer shall be placed outside the measurement chamber, which has consequences for SPV measurements at very short times. By varying the LCR circuit of a measurement configuration, applying a multi-parameter fit and simulating the corresponding SPV transients, we show, on the examples of highly doped silicon and a CdS thin film, that the source function of SPV transients can be reconstructed with a resolution time better than 1 ns.

2.
Psychol Med ; 46(11): 2275-86, 2016 08.
Article in English | MEDLINE | ID: mdl-27193073

ABSTRACT

BACKGROUND: Data on gender-specific profiles of cognitive functions in patients with Parkinson's disease (PD) are rare and inconsistent, and possible disease-confounding factors have been insufficiently considered. METHOD: The LANDSCAPE study on cognition in PD enrolled 656 PD patients (267 without cognitive impairment, 66% male; 292 with mild cognitive impairment, 69% male; 97 with PD dementia, 69% male). Raw values and age-, education-, and gender-corrected Z scores of a neuropsychological test battery (CERAD-Plus) were compared between genders. Motor symptoms, disease duration, l-dopa equivalent daily dose, depression - and additionally age and education for the raw value analysis - were taken as covariates. RESULTS: Raw-score analysis replicated results of previous studies in that female PD patients were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.03), while men outperformed women in visuoconstruction (p = 0.002) and figural memory (p = 0.005). In contrast, gender-corrected Z scores showed that men were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.02; recognition, p = 0.04), while no difference was found for visuospatial tests. This picture could be observed both in the overall analysis of PD patients as well as in a differentiated group analysis. CONCLUSIONS: Normative data corrected for gender and other sociodemographic variables are relevant, since they may elucidate a markedly different cognitive profile compared to raw scores. Our study also suggests that verbal memory decline is stronger in women than in men with PD. Future studies are needed to replicate these findings, examine the progression of gender-specific cognitive decline in PD and define different underlying mechanisms of this dysfunction.


Subject(s)
Cognitive Dysfunction/physiopathology , Dementia/physiopathology , Memory Disorders/physiopathology , Parkinson Disease/physiopathology , Verbal Learning/physiology , Aged , Aged, 80 and over , Cognitive Dysfunction/etiology , Dementia/etiology , Female , Humans , Male , Middle Aged , Parkinson Disease/complications , Sex Factors
3.
Fortschr Neurol Psychiatr ; 82(11): 640-5, 2014 Nov.
Article in German | MEDLINE | ID: mdl-25383931

ABSTRACT

The DemTect, a frequently used cognitive screening tool for the German-speaking population, has been proven to be age-, but not education-dependent. To date, scoring routines for persons under and over 60 years of age have been available. In order to describe the age-effect more specifically, the DemTect was administered to persons under 40 (n = 105; median 33 years [18 - 39]) and over 80 years of age [n = 68; median 83 years [80 - 93}). After transformation of the raw scores, which are based on the mean and standard deviation of the respective reference group, an adequate attribution of scores could be achieved and no differences between the groups can be observed in the total score or the subtest scores. The median of the transformed total score was 16 [5 ­ 18] for the younger and 15 [5 ­ 18] for the older age group. The new scoring routines supplement the scoring procedures of the DemTect for these age groups.


Subject(s)
Cognition Disorders/diagnosis , Neuropsychological Tests/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Cognition Disorders/psychology , Dementia/diagnosis , Dementia/psychology , Female , Germany , Humans , Language , Male , Middle Aged , Neuropsychological Tests/standards , Reference Standards , Reproducibility of Results , Young Adult
4.
Rev Sci Instrum ; 85(6): 065105, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24985850

ABSTRACT

Contactless measurements of the lifetime of charge carriers are presented with varying ways of photo excitation: with and without bias light and pulsed and frequency modulated. These methods are applied to the study of the surface passivation of single crystalline silicon by a-SiN(x):H and Al2O3 coatings. The properties of these coatings are investigated under consideration of the merits of the different methods.

5.
Plant Biol (Stuttg) ; 16 Suppl 1: 120-8, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23870071

ABSTRACT

Callus cell cultures of Arabidopsis thaliana (cv. Columbia) were exposed to parabolic flights in order to assess molecular, short-term responses to altered gravity fields. Using transgenic cell lines, hydrogen peroxide (H2 O2 ) and cytosolic Ca(2+) were continuously monitored. In parallel, the metabolism of samples was chemically quenched (RNAlater, Ambion for RNA; acid/base for NADPH, NADP) at typical stages of a parabola [1 g before pull up; end of pull up (1.8 g), end of microgravity (20 s) and end of pull out (1.8 g)]. Cells exhibited an increase in both Ca(2+) and H2 O2 with the onset of microgravity, and a decline thereafter. This behaviour was accompanied by a decrease of the NADPH/NADP redox ratio, indicating Ca(2+) -dependent activation of a NADPH oxidase. Microarray analyses revealed concomitant expression profiles. At the end of the microgravity phase, 396 transcripts were specifically up-, while 485 were down-regulated. Up-regulation was dominated by Ca(2+) - and ROS-related gene products. The same material was also used for analysis of phosphopeptides with 2-D SDS PAGE. Relevant spots were identified by liquid chromatography-MS. With the exception of a chaperone (HSP 70-3), hypergravity (1.8 g) and microgravity modified different sets of proteins. These are partly involved in primary metabolism (glycolysis, gluconeogenesis, citrate cycle) and detoxification of ROS. Taken together, these data show that both gene expression and protein modulation jointly respond within seconds to alterations in the gravity field, with a focus on metabolic adaptation, signalling and control of ROS.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/cytology , Calcium/metabolism , Cytosol/metabolism , Gene Expression Regulation, Plant , Gravity, Altered , Hydrogen Peroxide/metabolism , Space Flight , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Cells, Cultured , Electrophoresis, Gel, Two-Dimensional , Intracellular Space/metabolism , Models, Biological , NADP/metabolism , Oligonucleotide Array Sequence Analysis , Oxidation-Reduction , Phosphoproteins/genetics , Phosphoproteins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Spectrometry, Fluorescence
7.
Biochem J ; 351 Pt 3: 639-47, 2000 Nov 01.
Article in English | MEDLINE | ID: mdl-11042118

ABSTRACT

We have isolated and characterized the cDNA encoding nucleoside triphosphate diphosphohydrolase 6 (NTPDase6), a novel member of the ecto-nucleoside triphosphate diphosphohydrolase family. The rat-brain-derived cDNA has an open reading frame of 1365 bp encoding a protein of 455 amino acid residues, a calculated molecular mass of 49971 Da and a predicted N-terminal hydrophobic sequence. It shares 86% sequence identity with the human CD39L2 sequence and 48% and 51% identity respectively with sequences of the two related human and murine nucleoside diphosphatases (CD39L4, NTPDase5/ER-UDPase). The mRNA was expressed in all tissues investigated, revealing two major transcripts with differing abundances. PCR analysis suggests a single open reading frame. A Myc-His-tagged NTPDase6 was expressed in Chinese hamster ovary (CHO) and PC12 cells for immunological analysis and protein isolation. The protein was contained in membrane fractions of transfected CHO cells and occurred in a soluble form in the cell culture supernatants. NTPDase6 preferentially hydrolysed nucleoside 5'-diphosphates. With different substrates the order of activity was GDP>IDP>>UDP,CDP>>ADP. Nucleoside 5'-triphosphates were hydrolysed only to a minor extent and no hydrolysis of nucleoside 5'-monophosphates was observed. The enzyme was strongly and equally activated by Ca(2+) and Mg(2+) and had a K(m) for GDP of 211 microM. The immunohistochemical analysis of transfected CHO and PC12 cells suggests that NTPDase6 is associated with the Golgi apparatus and to a small extent also with the plasma membrane. The enzyme might support glycosylation reactions in the Golgi apparatus and, when released from cells, might catalyse the hydrolysis of extracellular nucleotides.


Subject(s)
Apyrase/genetics , Pyrophosphatases/genetics , Amino Acid Sequence , Animals , Apyrase/chemistry , Apyrase/metabolism , Base Sequence , Blotting, Northern , CHO Cells , Catalysis , Cloning, Molecular , Cricetinae , DNA Primers , DNA, Complementary , Glycosylation , Golgi Apparatus/enzymology , Molecular Sequence Data , PC12 Cells , Phylogeny , Pyrophosphatases/chemistry , Pyrophosphatases/metabolism , Rats , Sequence Homology, Amino Acid
8.
Dis Colon Rectum ; 40(7): 832-4, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9221862

ABSTRACT

PURPOSE: Many operations have been described for the management of rectal prolapse. Despite an overall recurrence rate of greater than 15 percent, few reviews address how to deal with this problem. This report summarizes our experience with recurrent rectal prolapse and includes suggestions for reoperative management of failed repairs from both abdominal and perineal approaches. PATIENTS AND METHODS: Fourteen patients (3 male) ranging in age from 22 to 92 (mean, 68) years underwent operative correction of recurrent rectal prolapse. Average time from initial operation to recurrence was 14 (range, 6-60) months. Initial operations (before recurrence) were as follows: perineal proctectomy and levatorplasty (10), anal encirclement (2), Delorme's procedure (1), and anterior resection (1). Operative procedures performed for recurrence were as follows: perineal proctectomy and levatorplasty (7), sacral rectopexy (abdominal approach; 3), anterior resection with rectopexy (2), Delorme's procedure (1), and anal encirclement (1). Average length of follow-up was 50 (range, 9-115) months. RESULTS: No further episodes of complete rectal prolapse were observed during this period. Preoperatively, three patients were noted to be incontinent to the extent that necessitated the use of perineal pads. The reoperative procedures failed to restore fecal continence in any of these three individuals. One patient died in the postoperative period after anal encirclement from an unrelated cause. CONCLUSION: Surgical management of recurrent rectal prolapse can be expected to alleviate the prolapse, but not necessarily fecal incontinence. Perineal proctectomies can be safely repeated. Resectional procedures may result in an ischemic segment between two anastomoses, unless the surgeon can resect a previous anastomosis in the repeat procedure. Nonresectional procedures such as the Delorme's procedure should be strongly considered in the management of recurrent rectal prolapse if a resectional procedure was performed initially and failed.


Subject(s)
Rectal Prolapse/surgery , Abdomen/surgery , Adult , Aged , Aged, 80 and over , Anal Canal/blood supply , Anal Canal/surgery , Anastomosis, Surgical/adverse effects , Cause of Death , Fecal Incontinence/surgery , Female , Follow-Up Studies , Humans , Ischemia/etiology , Male , Middle Aged , Perineum/surgery , Rectum/blood supply , Rectum/surgery , Recurrence , Reoperation , Survival Rate , Time Factors , Treatment Outcome
9.
Am J Surg ; 173(3): 213-7, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9124629

ABSTRACT

BACKGROUND: We report our experience of 8 patients who underwent repair of iatrogenic rectourinary fistulae via the transsphincteric (York Mason) approach. PATIENTS AND METHODS: Eight patients developed rectourinary fistulae in the course of treatment of prostate cancer. Three fistulae developed after radiation therapy alone, three after prostatectomy, and two after both surgery and radiation therapy. Five patients underwent fecal diversion in conjunction with repair. RESULTS: All fistulae remained closed after repair. All patients were continent of stool after primary surgery or after colostomy closure if they had been diverted. Two patients had complications associated with urethral catheters that resolved with changing the catheters. CONCLUSION: The transsphincteric (York Mason) approach in the repair of rectourinary fistulae results in successful closure of the fistulae without impairment of continence to stool. This procedure is much simpler than complicated transabdominal or transperineal approaches to these fistulae.


Subject(s)
Rectal Fistula/surgery , Urinary Fistula/surgery , Aged , Humans , Male , Middle Aged , Postoperative Complications , Prostatectomy/adverse effects , Prostatic Neoplasms/radiotherapy , Prostatic Neoplasms/surgery , Radiation Injuries/surgery , Rectal Fistula/etiology , Surgical Procedures, Operative/methods , Urinary Fistula/etiology
10.
Dis Colon Rectum ; 38(3): 294-6, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7882796

ABSTRACT

PURPOSE: Patients who have undergone proctectomy without concomitant rectal reconstruction or coloanal anastomosis were not normally considered candidates for re-establishment of anal continuity until a case report published in 1985. With the addition of nine patients, reported herein is a series of ten patients who have undergone delayed pull-through procedures months to years after permanent proctectomy. PATIENTS: Ten patients (including the single case reported in 1985) have undergone delayed pull-through procedures up to 24 years after permanent proctectomy and ostomy formation. Delayed ileal pouch-anal anastomoses were performed in nine patients, and delayed coloanal anastomosis was performed in one patient. There were four males and six females, each of whom had evidence of external sphincter contraction on physical examination. Average age was 33 (range, 24-51) years at the time of reconstruction. Average duration of follow-up is 32 (range, 1-96) months. RESULTS: One patient is awaiting ileostomy closure. Five of nine patients use constipating agents. Two patients are constipated and use enemas to aid in evacuation. None are wearing protective undergarments. One patient had his ileostomy reconstructed eight years after delayed pull-through for uncontrollable diarrhea associated with chemotherapy for multiple myeloma and recently died. Postoperative complications included wound infection (3), enterocutaneous anastomotic stricture requiring anoplasty (2), small bowel obstruction (1), pneumonia (1), presacral abscess (1), and pouchitis (1). CONCLUSIONS: Delayed pull-through procedures performed months to years after permanent proctectomy can be performed in selected patients, with results comparable to rectal reconstruction done at the time of proctectomy.


Subject(s)
Anal Canal/surgery , Colon/surgery , Enterostomy , Proctocolectomy, Restorative , Rectum/surgery , Adult , Anastomosis, Surgical , Female , Humans , Male , Middle Aged , Reoperation , Time Factors
11.
Semin Surg Oncol ; 10(3): 200-7, 1994.
Article in English | MEDLINE | ID: mdl-8085097

ABSTRACT

Surgery is the primary mode of therapy for colorectal cancer. Advances beyond exteriorization began to appear at the end of the nineteenth century. The antibiotic era brought on more advances. Dogma abounds with respect to the technical aspects of surgery for colon and rectal cancer and few randomized, prospective trials have been done to evaluate the importance of these techniques. Firmly established are the techniques of resection of lymphatic drainage of tumors, en bloc resection of invaded structures, and obtaining at least 2 cm margins of rectal cancers. Radical lymph node dissection, luminal ligation, oophorectomy, and the "No-Touch Technique" are discussed. Despite the paucity of irrefutable scientific data to support many of the described surgical techniques, differences in outcome between surgeons suggest that technique is important. There is great need for randomized, prospective trials to evaluate the multitude of techniques described for the surgical treatment of colorectal cancer.


Subject(s)
Colonic Neoplasms/surgery , Neoplasm Recurrence, Local , Neoplasm Seeding , Rectal Neoplasms/surgery , Surgical Procedures, Operative/methods , Colectomy/methods , Colonic Neoplasms/mortality , Female , Humans , Male , Neoplasm Metastasis/prevention & control , Neoplasm Recurrence, Local/etiology , Neoplasm Recurrence, Local/prevention & control , Ovariectomy , Rectal Neoplasms/mortality , Surgical Procedures, Operative/adverse effects
12.
Mil Med ; 158(7): 480-4, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8351051

ABSTRACT

Prior studies have documented the ill effects of cigarette smoking on soldier athletic performance. We examined the effects, if any, of cigarette smoking and alcohol use on troop readiness. A group of 510 soldiers was examined. They answered an initial questionnaire and then were followed in sick call for a 2-month period. The results of the study confirmed that cigarette smoking impacted adversely on athletic performance. However, we were unable to quantitate increased time off or away from duty as a result of cigarette smoking and alcohol use.


Subject(s)
Alcohol Drinking/adverse effects , Military Personnel , Physical Fitness , Smoking/adverse effects , Absenteeism , Adolescent , Adult , Humans , United States
13.
Am Surg ; 56(6): 335-8, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2350105

ABSTRACT

Among patients with various malignancies, three to 15 per cent may have associated idiopathic thrombosis. In a two-year period, we saw three patients with signs and symptoms demonstrating the association of neoplasia and coagulopathy. Their clinical courses and eventual outcomes are summarized. All had thrombophlebitis of multiple sites. There were difficulties in demonstrating their underlying occult malignancies, and all three patients showed resistance to oral anticoagulation drugs. Current hypotheses concerning the pathophysiology of coagulopathy associated with cancer are discussed, and recommendations for management of such patients were presented.


Subject(s)
Adenocarcinoma/complications , Lung Neoplasms/complications , Thrombophlebitis/etiology , Adenocarcinoma/blood , Adult , Blood Coagulation/physiology , Female , Heparin/therapeutic use , Humans , Lung Neoplasms/blood , Male , Middle Aged , Thrombophlebitis/drug therapy , Warfarin/therapeutic use
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