387 research outputs found
SUSY approach to Pauli Hamiltonians with an axial symmetry
A two-dimensional Pauli Hamiltonian describing the interaction of a neutral
spin-1/2 particle with a magnetic field having axial and second order
symmetries, is considered. After separation of variables, the one-dimensional
matrix Hamiltonian is analyzed from the point of view of supersymmetric quantum
mechanics. Attention is paid to the discrete symmetries of the Hamiltonian and
also to the Hamiltonian hierarchies generated by intertwining operators. The
spectrum is studied by means of the associated matrix shape-invariance. The
relation between the intertwining operators and the second order symmetries is
established and the full set of ladder operators that complete the dynamical
algebra is constructed.Comment: 18 pages, 3 figure
Expression of GnRH receptor in the canine corpus luteum, and luteal function following deslorelin acetate-induced puberty delay
The goals of this study were as follows: (Experiment 1) to examine the basic capability of canine corpora lutea (CL) to respond to GnRH by assessing expression of gonadotropin-releasing hormone receptor (GnRH-R) in luteal samples collected throughout the luteal lifespan from non-pregnant dogs, and (Experiment 2) to investigate the effects of pre-pubertal application of the GnRH agonist deslorelin acetate on luteal function following the first oestrus. Mature CL were collected during the mid-luteal phase (days 30–45) from treated and control bitches. Transcript levels of several factors were determined: estrogen receptors (ESR1/ERα, ESR2/ERβ), progesterone (P4)-receptor (PGR), prolactin receptor (PRLR), PGE2-synthase (PTGES) and PGE2 receptors (PTGER2/EP2, PTGER4/EP4), vascular endothelial growth factor (VEGFA) and VEGF receptors (VEGFR1 and VEGFR2), cyclooxygenase 2 (COX2/PTGS2), steroidogenic acute regulatory protein (STAR) and 3β-hydroxysteroid dehydrogenase (3βHSD). Additionally, levels of Kisspeptin 1 (Kiss1) and its receptor (KISS1-R) were evaluated. Although generally low, GnRH-R expression was time dependent and was elevated during early dioestrus, with a significant decrease towards luteal regression. In deslorelin-treated and control dogs, its expression was either low or frequently below the detection limit. EP2 and VEGFR1 were higher in the treated group, which could be caused by a feedback mechanism after long-term suppression of reproductive activity. Despite large individual variations, 3βHSD was higher in the deslorelin-treated group. This, along with unchanged STAR expression, was apparently not mirrored in increased luteal functionality, because similar P4 levels were detected in both groups. Finally, the deslorelin-mediated long-term delay of puberty does not have negative carry-over effects on subsequent ovarian functionality in bitches
Localization of Dirac-like excitations in graphene in the presence of smooth inhomogeneous magnetic fields
The present article discusses magnetic confinement of the Dirac excitations
in graphene in presence of inhomogeneous magnetic fields. In the first case a
magnetic field directed along the z axis whose magnitude is proportional to
is chosen. In the next case we choose a more realistic magnetic field
which does not blow up at the origin and gradually fades away from the origin.
The magnetic fields chosen do not have any finite/infinite discontinuity for
finite values of the radial coordinate. The novelty of the two magnetic fields
is related to the equations which are used to find the excited spectra of the
excitations. It turns out that the bound state solutions of the two-dimensional
hydrogen atom problem are related to the spectra of graphene excitations in
presence of the (inverse-radial) magnetic field. For the other magnetic
field profile one can use the knowledge of the bound state spectrum of a
two-dimensional cut-off Coulomb potential to dictate the excitation spectra of
the states of graphene. The spectrum of the graphene excitations in presence of
the inverse-radial magnetic field can be exactly solved while the other case
cannot be. In the later case we give the localized solutions of the zero-energy
states in graphene.Comment: 9 pages, 6 figures, to appear in Journal of Physics: Condensed Matte
Low-cost liquid medium for in vitro cultivation of Leishmania parasites in low-income countries
Background: Cutaneous Leishmaniasis (CL) induced by Leishmania aethiopica
has two clinical manifestations: ulcerating, self-healing CL and
non-ulcerating, non-healing CL. The grossly disfiguring multiple nodules
on the face and exterior surface of limbs during non-ulcerative CL are
sometimes misdiagnosed as other skin infections. Thus the need for
definitive and prompt laboratory diagnosis will be required. Identifying
Leishmania parasite by culture method is considered as a definitive
method for initiation of treatment and as an effective component of
leishmaniasis control methods. Recently the involvement of Fas (CD95)
and Tumor Necrosis Factor (TNF) Related Apoptosis Inducing Ligand (TRAIL)
induced apoptotic pathways were proposed to be involved in tissue
destruction and ulceration during L. major induced CL.
Aims: 1) to develop an alternative culture media that could minimize the
cost for culturing Leishmania from patient lesions.
2) to investigate if the expression of FasL and TRAIL differs in
ulcerating and non- ulcerative CL.
Methods: GALF-1 media was formulated in our lab and compared to RPMI 1640
medium and conventional Locke s semi solid media (LSSM) which is one of
the modifications of Novy-MacNeal-Nicolle (NNN) culture media.
Amastigotes transformation, cryopreservation, recovery of parasites, cost
and mass cultivation were analysed. Expression of Fas ligand (FasL),
TRAIL and apoptosis were assessed by immunohistology in human skin
biopsies from L. aethiopica induced ulcerative or non-ulcerative CL. FasL
and TRAIL blocking experiments were performed in a murine model of CL.
Results and discussion: GALF-1 is cheap and its ingredients available in
a low income country such as Ethiopia. GALF-1 was able to transform
amastigotes from Ethiopian patients samples and could be used to
cultivate promastigotes in large quantities. Cost analysis showed 80% to
95 % decreased costs as compared to conventional media. Promastigotes
cultured with GALF-1 could be cryopreserved in liquid nitrogen with
comparable re-culture potential to conventional media. Affordability of
diagnostic assays is a key issue for resource poor countries and the
possibility to cut the cost of the efficient culture method for diagnosis
through the use of inexpensive local formulated reagents could improve
the diagnosis of leishmaniasis in low income endemic countries.
More FasL expressing cells were detected in dermis of ulcerative CL as
compared to non-ulcerative CL and controls. TRAIL expression was higher
in ulcerative CL as compared to non-ulcerative CL and controls in both
epidermis and dermis. Increased dermal expression of FasL and TRAIL was
associated with ulcer formation during CL. This correlated with an
inhibition of the ulcerative process in a murine CL model during FasL and
TRAIL neutralisation.The mechanisms of the involvement of FasL and TRAIL
in ulceration was not elucidated and putative reason(s) for the
difference in dysregulation of apoptosis are discussed
A Major Role for Perifornical Orexin Neurons in the Control of Glucose Metabolism in Rats
OBJECTIVE-The hypothalamic neuropeptide orexin influences (feeding) behavior as well as energy metabolism. Administration of exogenous orexin-A into the brain has been shown to increase both food intake and blood glucose levels. In the present study, we investigated the role of endogenous hypothalamic orexin release in glucose homeostasis in rats. RESEARCH DESIGN AND METHODS-We investigated the effects of the hypothalamic orexin system on basal endogenous glucose production (EGP) as well as on hepatic and peripheral insulin sensitivity by changing orexinergic activity in the hypothalamus combined with hepatic sympathetic or parasympathetic denervation, two-step hyperinsulinemic-euglycemic clamps, immunohistochemistry, and RT-PCR studies. RESULTS-Hypothalamic disinhibition of neuronal activity by the gamma-aminobutyric acid receptor antagonist bicuculline (BIC) increased basal EGP, especially when BIC was administered in the perifornical area where orexin-containing neurons but not melanocortin-concentrating hormone-containing neurons were activated. The increased BIC-induced EGP was largely prevented by intracerebroventricular pretreatment with the orexin-1 receptor antagonist. Intracerebroventricular administration of orexin-A itself caused an increase in plasma glucose and prevented the daytime decrease of EGP. The stimulatory effect of intracerebroventricular orexin-A on EGP was prevented by hepatic sympathetic denervation. Plasma insulin clamped at two or six times the basal levels did not counteract the stimulatory effect of perifornical BIC on EGP, indicating hepatic insulin resistance. RT-PCR showed that stimulation of orexin neurons increased the expression of hepatic glucoregulatory enzymes. CONCLUSIONS-Hypothalamic orexin plays an important role in EGP, most likely by changing the hypothalamic output to the autonomic nervous system. Disturbance of this pathway may result in unbalanced glucose homeostasis. Diabetes 58:1998-2005, 200
Feasibility study of intelligent autonomous determination of the bladder voiding need to treat bedwetting using ultrasound and smartphone ML techniques
Unsatisfactory cure rates for the treatment of nocturnal enuresis (NE), i.e. bed-wetting, have led to the need to explore alternative modalities. New treatment methods that focus on preventing enuretic episodes by means of a pre-void alerting system could improve outcomes for children with NE in many aspects. No such technology exists currently to monitor the bladder to alarm before bed-wetting. The aim of this study is to carry out the feasibility of building, refining and evaluating a new, safe, comfortable and non-invasive wearable autonomous intelligent electronic device to monitor the bladder using a single-element low-powered low-frequency ultrasound with the help of Machine Learning techniques and to treat NE by warning the patient at the pre-void stage, enhancing quality of life for these children starting from the first use. The sensitivity and specificity values are 0.89 and 0.93 respectively for determining imminent voiding need. The results indicate that customised imminent voiding need based on the expansion of the bladder can be determined by applying a single-element transducer on a bladder in intermittent manner. The acquired results can be improved further with a comfortable non-invasive device by adding several more features to the current features employed in this pilot study
Treatment of stage I-III periodontitis-The EFP S3 level clinical practice guideline
Background: The recently introduced 2017 World Workshop on the classification of periodontitis, incorporating stages and grades of disease, aims to link disease classification with approaches to prevention and treatment, as it describes not only disease severity and extent but also the degree of complexity and an individual's risk. There is, therefore, a need for evidence-based clinical guidelines providing recommendations to treat periodontitis. Aim: The objective of the current project was to develop a S3 Level Clinical Practice Guideline (CPG) for the treatment of Stage I–III periodontitis. Material and Methods: This S3 CPG was developed under the auspices of the European Federation of Periodontology (EFP), following the methodological guidance of the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The rigorous and transparent process included synthesis of relevant research in 15 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and consensus, on those recommendations, by leading experts and a broad base of stakeholders. Results: The S3 CPG approaches the treatment of periodontitis (stages I, II and III) using a pre-established stepwise approach to therapy that, depending on the disease stage, should be incremental, each including different interventions. Consensus was achieved on recommendations covering different interventions, aimed at (a) behavioural changes, supragingival biofilm, gingival inflammation and risk factor control; (b) supra- and sub-gingival instrumentation, with and without adjunctive therapies; (c) different types of periodontal surgical interventions; and (d) the necessary supportive periodontal care to extend benefits over time. Conclusion: This S3 guideline informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat periodontitis and to maintain a healthy dentition for a lifetime, according to the available evidence at the time of publication
Transperineal prostate biopsies for diagnosis of prostate cancer are well tolerated: a prospective study using patient-reported outcome measures
We aimed to determine short-term patient-reported outcomes in men having general anesthetic transperineal (TP) prostate biopsies. A prospective cohort study was performed in men having a diagnostic TP biopsy. This was done using a validated and adapted questionnaire immediately post-biopsy and at follow-up of between 7 and 14 days across three tertiary referral hospitals with a response rate of 51.6%. Immediately after biopsy 43/201 (21.4%) of men felt light-headed, syncopal, or suffered syncope. Fifty-three percent of men felt discomfort after biopsy (with 95% scoring <5 in a 0-10 scale). Twelve out of 196 men (6.1%) felt pain immediately after the procedure. Despite a high incidence of symptoms (e.g., up to 75% had some hematuria, 47% suffered some pain), it was not a moderate or serious problem for most, apart from hemoejaculate which 31 men suffered. Eleven men needed catheterization (5.5%). There were no inpatient admissions due to complications (hematuria, sepsis). On repeat questioning at a later time point, only 25/199 (12.6%) of men said repeat biopsy would be a significant problem despite a significant and marked reduction in erectile function after the procedure. From this study, we conclude that TP biopsy is well tolerated with similar side effect profiles and attitudes of men to repeat biopsy to men having TRUS biopsies. These data allow informed counseling of men prior to TP biopsy and a benchmark for tolerability with local anesthetic TP biopsies being developed for clinical use.Boris Hadaschik received funding from the German Research Foundation and the European Foundation for Urology. Karan Wadhwa is sponsored by a Medical Research Council Research Training Fellowship. No other funding was received for this work
Prevention and treatment of peri-implant diseases—The EFP S3 level clinical practice guideline
Background: The recently published Clinical Practice Guidelines (CPGs) for the treatment of stages I–IV periodontitis provided evidence-based recommendations for treating periodontitis patients, defined according to the 2018 classification. Peri-implant diseases were also re-defined in the 2018 classification. It is well established that both peri-implant mucositis and peri-implantitis are highly prevalent. In addition, peri-implantitis is particularly challenging to manage and is accompanied by significant morbidity. Aim: To develop an S3 level CPG for the prevention and treatment of peri-implant diseases, focusing on the implementation of interdisciplinary approaches required to prevent the development of peri-implant diseases or their recurrence, and to treat/rehabilitate patients with dental implants following the development of peri-implant diseases. Materials and Methods: This S3 level CPG was developed by the European Federation of Periodontology, following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, formulation of specific recommendations, and a structured consensus process involving leading experts and a broad base of stakeholders. Results: The S3 level CPG for the prevention and treatment of peri-implant diseases culminated in the recommendation for implementation of various different interventions before, during and after implant placement/loading. Prevention of peri-implant diseases should commence when dental implants are planned, surgically placed and prosthetically loaded. Once the implants are loaded and in function, a supportive peri-implant care programme should be structured, including periodical assessment of peri-implant tissue health. If peri-implant mucositis or peri-implantitis are detected, appropriate treatments for their management must be rendered. Conclusion: The present S3 level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to maintain healthy peri-implant tissues, and to manage peri-implant diseases, according to the available evidence at the time of publication
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