Search

In this paper we present time-dependent perturbations of second-order non-autonomous abstract Cauchy problems associated to a family of operators with constant domain. We make use of the equivalence to a first-order non-autonomous abstract Cauchy problem in a product space, which we elaborate in full detail. As an application we provide a perturbed non-autonomous wave equation. [ABSTRACT FROM AUTHOR]

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory disease that is highly correlated with obesity. Haptoglobin serum levels have recently been recognized as an important biomarker linking obesity with chronic inflammation. Objective: To compare haptoglobin with previously proposed serum biomarkers for the determination of disease severity in HS patients. For this purpose, disease severity of HS patients was determined by a panel of clinical scores as well as several risk factors, such as weight and smoking habits. Methods: A prospective, diagnostic accuracy study was performed at the International Centre for Hidradenitis suppurativa/Acne inversa Bochum (ICH). The study included a total of 263 patients, including 131 who had a confirmed diagnosis of HS in Hurley I (n = 16), II (n = 56) and III (n = 59) HS, and 132 healthy controls. The main outcome was to identify serological inflammatory markers for HS disease severity [severe (III) vs. moderate/mild (II/I)] as assessed by Hurley classification. Results: The serum levels of acute phase proteins haptoglobin and CRP, as well as the number of neutrophils in peripheral blood, number of monocytes, the systemic immune‐inflammation index and the pan‐immune‐inflammatory value correlated with disease severity according to established clinical scores (mHSS, SAHS, Hurley, DLQI). HS patients had significantly higher haptologlobin levels compared to healthy controls. Logistic regression analysis revealed haptoglobin as the only independent marker predicting severe HS. Conclusion: In this prospective study, we discovered that the serum levels of the acute phase protein haptoglobin levels serve as an independent marker of disease severity in HS. While this presents the first study in the context of HS. Thus, the present data not only yield a highly promising serum marker to be further validated. [ABSTRACT FROM AUTHOR]

Summary: Four machine learning models were developed and compared to predict the risk of a future major osteoporotic fracture (MOF), defined as hip, wrist, spine and humerus fractures, in patients with a prior fracture. We developed a user-friendly tool for risk calculation of subsequent MOF in osteopenia patients, using the best performing model. Introduction: Major osteoporotic fractures (MOFs), defined as hip, wrist, spine and humerus fractures, can have serious consequences regarding morbidity and mortality. Machine learning provides new opportunities for fracture prediction and may aid in targeting preventive interventions to patients at risk of MOF. The primary objective is to develop and compare several models, capable of predicting the risk of MOF as a function of time in patients seen at the fracture and osteoporosis outpatient clinic (FO-clinic) after sustaining a fracture. Methods: Patients aged > 50 years visiting an FO-clinic were included in this retrospective study. We compared discriminative ability (concordance index) for predicting the risk on MOF with a Cox regression, random survival forests (RSF) and an artificial neural network (ANN)-DeepSurv model. Missing data was imputed using multiple imputations by chained equations (MICE) or RSF's imputation function. Analyses were performed for the total cohort and a subset of osteopenia patients without vertebral fracture. Results: A total of 7578 patients were included, 805 (11%) patients sustained a subsequent MOF. The highest concordance-index in the total dataset was 0.697 (0.664–0.730) for Cox regression; no significant difference was determined between the models. In the osteopenia subset, Cox regression outperformed RSF (p = 0.043 and p = 0.023) and ANN-DeepSurv (p = 0.043) with a c-index of 0.625 (0.562–0.689). Cox regression was used to develop a MOF risk calculator on this subset. Conclusion: We show that predicting the risk of MOF in patients who already sustained a fracture can be done with adequate discriminative performance. We developed a user-friendly tool for risk calculation of subsequent MOF in patients with osteopenia. [ABSTRACT FROM AUTHOR]

Copyright of Manuelle Medizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Schmerz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Zinc deficiency‐like (ZDL) syndrome is an inherited defect of Fleckvieh calves, with striking similarity to bovine hereditary zinc deficiency (BHZD). However, the causative mutation in a phospholipase D4 encoding gene (PLD4) shows no connection to zinc metabolism. Objectives: To describe clinical signs, laboratory variables, and pathological findings of ZDL syndrome and their utility to differentiate ZDL from BHZD and infectious diseases with similar phenotype. Animals: Nine hospitalized calves with crusting dermatitis and confirmed mutation in PLD4 and medical records from 25 calves with crusting dermatitis or suspected zinc deficiency. Methods: Prospective and retrospective case series. Results: The 9 calves (age: 5–53 weeks) displayed a moderate to severe crusting dermatitis mainly on the head, ventrum, and joints. Respiratory and digestive tract inflammations were frequently observed. Zinc supplementation did not lead to remission of clinical signs in 4 calves. Laboratory variables revealed slight anemia in 8 calves, hypoalbuminemia in 6 calves, but reduced serum zinc concentrations in only 3 calves. Mucosal erosions/ulcerations were present in 7 calves and thymus atrophy or reduced thymic weights in 8 calves. Histologically, skin lesions were indistinguishable from BHZD. Retrospective analysis of medical records revealed the presence of this phenotype since 1988 and pedigree analysis revealed a common ancestor of several affected calves. Conclusions and Clinical Importance: ZDL syndrome should be suspected in Fleckvieh calves with crusting dermatitis together with diarrhea or respiratory tract inflammations without response to oral zinc supplementation. Definite diagnosis requires molecular genetic confirmation of the PLD4 mutation. [ABSTRACT FROM AUTHOR]

Background: First episode genital herpes simplex virus (HSV) infections can be classified into three groups, primary genital herpes (no previous exposure to HSV), non-primary first episode (IgG antibody to HSV of the non-presenting type), and first episode with pre-existing IgG HSV antibodies. The use of IgM to classify first episode genital herpes has not been evaluated.Objective: To evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of HSV-1 and HSV-2 IgM antibodies for the diagnosis of first episode genital herpes, when compared with clinical diagnosis.Methods: Patients with a first clinical episode of genital herpes were recruited. Sera were tested for IgG antibodies to HSV-2 using an indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. HSV-1 IgG and IgM and HSV-2 IgM antibodies were detected using western blot.Results: 157 patients were recruited. 31 were excluded (missing data or no detectable antibodies and negative viral isolation). Therefore, 126 patients were included in the analysis. 23 (18.3%) had primary genital herpes, 34 (27.0%) non-primary first episode, and 69 (54.8%) had pre-existing genital herpes. The specificity and PPV of HSV IgM was 100%; the sensitivity was 79% and the NPV 85%.Conclusion: IgM HSV serology may be useful in the management of some patients with first episode genital herpes and provide an indication of the source of infection. Drawbacks include the low sensitivity and NPV, lack of availability, IgM antibodies may occasionally be produced in response to recurrent infection and, finally, IgM antibodies may take up to 10 days to develop and last 7-10 days. [ABSTRACT FROM AUTHOR]

This paper explores the use of heuristics as cognitive strategies invoked during the process of design. Heuristics are reasoning processes that do not guarantee the best solution, but often lead to potential solutions by providing a simple cognitive "shortcut."We propose that designers use specific design heuristics to explore the problem space of potential designs, leading to the generation of creative solutions. We test whether design heuristics can be taught to novices, and suggest their use will facilitate the design process at multiple levels of instruction. In the present empirical study, we evaluate a set of six instructional heuristics and validate their effectiveness with product concepts generated by novice designers. Six hundred seventy-three drawings were created by 120 first-year college students under four instructional conditions. Drawings were coded according to their content, use of heuristics, creativity, and practicality. The most creative concepts emerged from the experimental conditions where heuristics were introduced. Heuristics appeared to help the participants "jump" to a new problem space, resulting in more varied designs, and a greater frequency of designs judged as more creative. Our findings suggest that simple demonstration of design heuristics may, at times, be sufficient to stimulate divergent thinking, perhaps because these heuristics are readily grasped and contextual application is not required. Based on these findings, a conceptual model for design education emphasizing the importance of using a variety of heuristics is proposed. This model suggests that learning can be enhanced through exposure to a variety of design heuristics, and can supplement formal education and foster personal development in design learning. [ABSTRACT FROM AUTHOR]

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sexual behaviour is determined by social, cultural and personal factors. Sexual behaviour studies have been conducted in many countries. However, information from Australia is limited. This study was conducted in Obstetrics Department, Westmead Hospital, Sydney. Questionnaire-derived demographic and behavioural characteristics for public and private patients were compared using bivariate and logistic regression analyses. Of the patients, 3036 were public, and 595 private. On bivariate analysis some significant differences were private patients more likely to be born in Australia and have a higher education level whereas public patients were more likely to have had a greater number of lifetime sexual partners and younger age at first sex. Public patients were more likely to be herpes simplex virus type 2 (HSV-2) antibody positive (12%) than private patients (6%). On logistic regression significant variables included country of birth, being HSV-2 antibody positive, and age at first sex. A number of sexual and social variables were significantly different, comparing patients in the public and private sectors. Evaluation of interventions to reduce the sexual risk to women in the public sector should be considered, including encouraging young women to delay their sexual debut, and reducing the number of sexual partners. [ABSTRACT FROM AUTHOR]

Background: Neonatal herpes is a condition with high morbidity and mortality. The greatest risk occurs when the mother acquires herpes simplex virus (HSV) towards the end of pregnancy. A study from Seattle has suggested that the risk of acquisition of HSV during pregnancy was 3.7%. In Australia, HSV-2 infection is less common in pregnant women than in the United States. Consequently we conducted a study to establish HSV seroprevalence and the rate of HSV seroconversion in this population.Methods: The study was conducted at Westmead Hospital, Sydney, between June 1995 and April 1998. Women completed a questionnaire covering risk factors for the acquisition of genital herpes. A serum sample during pregnancy and a specimen of cord blood were obtained and tested for antibodies to HSV-2 using a type specific indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. A subset of the paired sera was tested for antibodies to HSV-1. The data were analysed using SPSS.Results: 326 of the 2616 (12.5%) women were HSV-2 seropositive. Three women (0.15%) acquired HSV-2 infection during pregnancy. None of the three babies of these mothers developed neonatal herpes. 416 maternal cord pairs were tested for HSV-1 antibodies and 330 (79.3%) were positive. No HSV-1 seroconversions occurred.Conclusions: In this population, HSV acquisition was uncommon (0.34% per year) and neonatal herpes was rare. A cost effective analysis suggested that type specific serology to screen pregnant women and their partners in low prevalence communities was not cost effective. [ABSTRACT FROM AUTHOR]

Before and 7–12 days after an Himalayan expedition CO2 equilibration curves were determined in the blood plasma of 12 mountaineers by in vitro and in vivo CO2 titration; in vivo osmolality changes (ΔOsm · Δ PCO2 −1, ΔOsm · ΔpH−1, where PCO2 is the partial pressure of CO2) during the latter experiments yielded estimates of whole body CO2 storage. In vitro −Δ[HCO3 −] · ΔpH−1 [nonbicarbonate buffer capacity (β) of blood] was increased 7 days after descent [before 31.3 (SEM 0.4) mmol · kgH2O−1, after 38.3 (SEM 3.9) mmol · kgH2O−1; P<0.05] resulting from an increased proportion of young erythrocytes; in additional experiments an augmented β was found in young (low density cells) compared to old cells [<1.097 g · ml−1: 0.216 (SEM 0.028) mmol · gHb−1, >1.100 g · ml−1: 0.145 (SEM 0.013) mmol · gHb−1, where Hb is haemoglobin; P<0.02]. In spite of increased Hb mass in vivo Δ[CO2total] · Δ PCO2 −1 [0.192 (SEM 0.010) mmol · kgH2O−1 · mmHg−1] and −Δ[HCO3 −] · ΔpH−1 [17.9 (SEM 1.0) mmol · kgH2O−1] as indicators of extracellular β rose only slightly after altitude (7 days +16%, P<0.02; +7%, NS) because of haemodilution. The ΔOsm · Δ PCO2 −1 [0.230 (SEM 0.015) mosmol · kgH2O−1 · mmHg−1] remained unchanged. Prealtitude differences in ΔOsm · ΔpH−1 between hypercapnia [−41 (SEM 5) mosmol · kgH2O−1] and hypo-capnia [−20 (SEM 3) mosmol · kgH2O−1; P<0.01] disappeared temporarily after return since the former slope was reduced. The high value during hypercapnia before ascent probably resulted from mechanisms stabilizing intracellular pH during moderate hypercapnia which were attenuated after descent. [ABSTRACT FROM AUTHOR]

Modifications of drug-induced V inhibition by the combined treatment of the cardiac membrane with several class 1 antiarrhythmic agents were studied in guinea pig's ventricular myocardium taking the depression of upstroke velocity in fast action potentials as an indicator for I blockade. A novel analytical procedure, first beat phasic block determination, provided the opportunity to estimate phasic drug binding initiated by a single action potential. [ABSTRACT FROM AUTHOR]

In microelectrode experiments on isolated papillary muscles of guinea-pigs, the effect of propafenone (1×10 mol/l-1×10 mol/l) on the fast Na action potential was analyzed. Propafenone caused, without changing the resting potential, a concentration dependent decrease of $$\dot V_{\max } $$ . At continuous stimulation with a rate of 12/min, complete inhibition of $$\dot V_{\max } $$ appeared in response to 1×10 mol/l. Transformation of the concentration-response curve into the Hill form revealed a Hill coefficient of 1.8. Some minor changes of the action potential configuration occurred consisting of a plateau shift to less positive potentials and of an abbreviation of action potential duration. Propafenone did not alter the linear dependence of $$\dot V_{\max } $$ on the logarithm of external Na concentration. Propafenone shifted the curve relating $$\dot V_{\max } $$ to membrane potential ( h-curve) to more negative potentials suggesting an interference with the inactivation process of the fast Na system. This effect developed on the quiescent, non-stimulated preparation and leads to the occurrence of a resting-state block being, consequently, potential dependent. Repetitive stimulation enhanced the propafenone-induced inhibition indicating a use-dependent block. During a train of 5-7 (at 12/min) or 15-20 (at 120/min) action potentials, a continuous decline of $$\dot V_{\max } $$ occurred until a new steady-state was attained. The interstimulus interval determined strength and kinetics of development (τ) of the use-dependent block. It was 22% and 8.4s, respectively at 5000 ms, but 70% and 1.8 s, respectively, at 500 ms. A slight intensification could also be induced by a decrease of membrane potential whilst pH or temperature changes remained ineffective. After cessation of continuous stimulation, the use-dependent block disappeared with a time constant of 15.5 s. Neither an increase of pH from 7.4 to 8.4 nor a decrease to 6.4 had any influence on the action of propafenone ( pK=9.0). Resting-state and usedependent block were of an identical amount regardless of the pH in the medium. [ABSTRACT FROM AUTHOR]

Drug-induced depression of I was studied in microelectrode experiments on papillary muscles of guinea pigs by taking $$\dot V_{\max } $$ of the fast Na action potential as an estimate for g thereby systematically discriminating between tonic and phasic blockade. [ABSTRACT FROM AUTHOR]