18 research outputs found

    Magnetic Field induced Dimensional Crossover Phenomena in Cuprate Superconductors and their Implications

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    We discuss the occurrence of crossing points in the magnetization - temperature (m,T(m,T) plane within the framework of critical phenomena. It is shown that in a two-dimensional superconducting slab of thickness dsd_{s} mz(δ)m_{z}(\delta) versus temperature TT curves measured in different fields H=H(0,sin⁥(δ),cos⁥(δ))\mathbf{H} = H(0,\sin (\delta) ,\cos (\delta)) will cross at the critical temperature T_c of the slab. In contrast, in a 3D anisotropic bulk superconductor the crossing point occurs in the plot mz(δ)/Hz1/2m_{z}(\delta) /H_{z}^{1/2} versus TT. The experimental facts that 2D crossing point features have been observed in ceramics and in single crystals for H\mathbf{H} close to H=H(0,0,1)\mathbf{H} = H(0,0,1), but not for H=H(0,1,0)\mathbf{H} = H(0,1,0), is explained in terms of an angle-dependent crossover field separating the regions where 2D or 3D thermal fluctuations dominate. The measured 2D-crossing point data are used to estimate one of the fundamental parameters of cuprate superconductors, the minimum thickness of the slab (ds)(d_{s}), which remains superconducting. Our estimates, based on experimental 2D-crossing point data for single crystals, reveal that this length adopts material dependent values. Therefore, experimental data for T_c and Ν∼2(T=0)\lambda_{\Vert}^{2}(T=0), plotted in terms of T_c versus 1/Ν∼2(T=0)1/\lambda_{\Vert}^{2}(T=0) will not tend to a straight line with universal slope as the underdoped limit is approached. Implications for magnetic torque measurements are also worked out

    Innovative Biosensing Approaches for Swift Identification of Candida Species, Intrusive Pathogenic Organisms

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    Candida is the largest genus of medically significant fungi. Although most of its members are commensals, residing harmlessly in human bodies, some are opportunistic and dangerously invasive. These have the ability to cause severe nosocomial candidiasis and candidemia that affect the viscera and bloodstream. A prompt diagnosis will lead to a successful treatment modality. The smart solution of biosensing technologies for rapid and precise detection of Candida species has made remarkable progress. The development of point-of-care (POC) biosensor devices involves sensor precision down to pico-/femtogram level, cost-effectiveness, portability, rapidity, and user-friendliness. However, futuristic diagnostics will depend on exploiting technologies such as multiplexing for high-throughput screening, CRISPR, artificial intelligence (AI), neural networks, the Internet of Things (IoT), and cloud computing of medical databases. This review gives an insight into different biosensor technologies designed for the detection of medically significant Candida species, especially Candida albicans and C. auris, and their applications in the medical setting

    The Flux-Line Lattice in Superconductors

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    Magnetic flux can penetrate a type-II superconductor in form of Abrikosov vortices. These tend to arrange in a triangular flux-line lattice (FLL) which is more or less perturbed by material inhomogeneities that pin the flux lines, and in high-TcT_c supercon- ductors (HTSC's) also by thermal fluctuations. Many properties of the FLL are well described by the phenomenological Ginzburg-Landau theory or by the electromagnetic London theory, which treats the vortex core as a singularity. In Nb alloys and HTSC's the FLL is very soft mainly because of the large magnetic penetration depth: The shear modulus of the FLL is thus small and the tilt modulus is dispersive and becomes very small for short distortion wavelength. This softness of the FLL is enhanced further by the pronounced anisotropy and layered structure of HTSC's, which strongly increases the penetration depth for currents along the c-axis of these uniaxial crystals and may even cause a decoupling of two-dimensional vortex lattices in the Cu-O layers. Thermal fluctuations and softening may melt the FLL and cause thermally activated depinning of the flux lines or of the 2D pancake vortices in the layers. Various phase transitions are predicted for the FLL in layered HTSC's. The linear and nonlinear magnetic response of HTSC's gives rise to interesting effects which strongly depend on the geometry of the experiment.Comment: Review paper for Rep.Prog.Phys., 124 narrow pages. The 30 figures do not exist as postscript file

    Philosophy of law in the Soviet Union and the people’s democracies

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    The fate of Marxism in the Soviet Union and the people’s democracies as the former’s extension owing to post-WWII occupation was from the beginning sealed by Bolshevism, that is, the politico-ideological domination and use of the scholarly domain as well, made to self-close in a merely justificatory role. There may have been attempts at opening, even if only conceivable within—i.e. preserving at the same time—this framework function. In the present conspectus, the limiting positions are occupied by the Soviet Union and the German Democratic Republic, completed by after-1968 Czechoslovakia, as well as Yugoslavia and pre-1968 Czechoslovakia, representing the substitute-to-religion dogmatic side, exclusively politically motivated in the former and subordinated to a humanising tendency in the latter case, on the one hand, and Poland, dedicated to a purely analytical approach, in which Marxism has simply no relevance, on the other. Hungary, treated in an earlier paper by the author, was in-between, taking Marxism seriously but mostly as a methodology, and thereby able to foster live debates. All that notwithstanding, there has been quite a few progressive moves also in Romania and Bulgaria in this specific academic field. Turning topoi of the discussions were, chronologically but recurrent transubstantiatedly, the exclusivity of Vyshinsky’s socialist normativism, the consequences ensuing from the law’s superstructural nature, the discontinuity vs. continuity of law in historical development, and, in the background, the dilemma of the ontological/epistemological understanding of Marxism, the latter standing for a rigid Leninist reducibility of law to its material substratum as the product of sheer reflection, and the former enabling to develop the law’s relative autonomy as in Lukács’ posthumous ontology. On the final analysis, all these forced paths made a whole region’s efforts to be belated as compared to international developments, the fact notwithstanding those outstanding achievements were born especially on the fields of legal ontology and sociology, as well as the legal methodology and particularly that of the comparison of laws

    Comparison of Type I and Type III Collagen Concentration between <i>Oreochromis mossambicus</i> and <i>Oreochromis niloticus</i> in Relation to Skin Scaffolding

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    Background and Objectives: Skin scaffolding can be done using allografts and autografts. As a biological allograft, the skin of Oreochromis niloticus (ON) has been used due to its high type I and III collagen content. Oreochromis mossambicus (OM) is also a member of the Oreochromis family, but not much is known regarding its collagen content. As such, this study aimed to assess and compare the collagen content of the two fish species. Materials and Methods: This is a crossover study comparing the skin collagen contents of the two fish. Young fish were chosen, as they tend to have higher collagen concentrations. The skin samples were sterilized in chlorhexidine and increasing glycerol solutions and analyzed histochemically with Sirius red picrate under polarized light microscopy. Results: 6 young ON and 4 OM specimens were used. Baseline type I collagen was higher for OM, but at maximum sterilization it was higher for ON, with no differences in between Type III collagen was higher for OM across all comparisons with the exception of the last stage of sterilization. Generally, collagen concentrations were higher in highly sterilized samples. Conclusions: OM skin harvested from young fish, with its greater collagen III content may be a better candidate for use as a biological skin scaffold in the treatment of burn wounds, compared to ON

    Diagnosis and Management of Febrile Neutropenia in Pediatric Oncology Patients—A Systematic Review

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    Infectious diseases are associated with a high morbidity and mortality rate among pediatric cancer patients undergoing treatment or receiving a transplant. Neutropenia represents a potentially fatal complication of cancer treatment and is associated with a high risk of developing bacterial infections. Although febrile neutropenia (FN) can affect both adults and children, the latter has a higher chance of infections with an unknown origin. Prompt empiric broad-spectrum antibiotic administration is collectively considered the best therapeutic approach. This review aims to analyze the latest works from the literature regarding the therapeutic strategies, schemes, and approaches and the efficacy of these in pediatric febrile neutropenia. Following PRISMA guidelines, an advanced search on PubMed, Scopus, and Cochrane Library, using the keywords “febrile neutropenia”, “pediatric”, “cancer”, and “oncology”, was performed. A total of 197 articles were found to be eligible. After screening the abstracts and excluding unfit studies, 16 articles were analyzed. There were eight retrospective studies, five prospective studies, and two clinical trials. Altogether, these studies have described around 5000 episodes of FN. The median age of the participants was 7.6 years, and the underlying condition for most of them was acute leukemia. The infectious agent could only be determined in around one-fifth of cases, from which 90% were of bacterial origin. As such, empirical broad-spectrum antibiotics are used, with the most used treatment scheme comprising third- and fourth-generation cephalosporins and antipseudomonal penicillins. In order to improve the treatment strategies of FN episodes and to successfully de-escalate treatments toward narrower-spectrum antibiotics, hospitals and clinics should increase their efforts in identifying the underlying cause of FN episodes through blood culture urine culture and viral tests, wherever infrastructure enables it

    Factors Contributing to Surgical Site Infections: A Comprehensive Systematic Review of Etiology and Risk Factors

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    Surgical site infections persist as a substantial concern within the realm of hospital-acquired infections. This enduring issue is further compounded by the mounting challenge of antibiotic resistance, a surge in surgical interventions, and the presence of comorbidities among patients. Thus, a comprehensive exploration of all discernible risk factors, as well as proactive preventive and prophylactic strategies, becomes imperative. Moreover, the prevalence of multidrug-resistant microorganisms has reached alarming proportions. Consequently, there is an acute need to investigate and scrutinize all potential therapeutic interventions to counter this burgeoning threat. Consequently, the primary objective of this review is to meticulously assess the origins and risk elements intertwined with surgical site infections across a diverse spectrum of surgical procedures. As the medical landscape continues to evolve, this critical analysis seeks to provide a nuanced understanding of the multi-faceted factors contributing to surgical site infections, with the overarching aim of facilitating more effective management and mitigation strategies. By exploring these dimensions comprehensively, we endeavor to enhance patient safety and the quality of surgical care in this era of evolving healthcare challenges

    Antibiotic Resistance Patterns of Uropathogens Causing Urinary Tract Infections in Children with Congenital Anomalies of Kidney and Urinary Tract

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    Background: Urinary tract infections (UTI) are common in children worldwide. Congenital anomalies of kidney and urinary tract (CAKUT) increase the risk of UTI and consequently antibiotic resistance. Antibiotic resistance represents an important public health issue worldwide. We aimed to evaluate the local trend in terms of bacterial uropathogen resistance in the western part of Romania in children with CAKUT and UTI. Methods: 252 children with CAKUT were admitted to our hospital over a five-year period. Of them, 91 developed at least one UTI episode, with a total number of 260 positive urine cultures. We collected data about age at diagnosis of CAKUT, sex, origin environment, type and side of CAKUT, number of UTIs, type of uropathogen, and uropathogens antibiotic resistance. Results: Distribution of uropathogens was Escherichia coli (38.84%), Klebsiella spp. (21.15%), Enterococcus spp. (15.76%), Proteus spp. (8.07%), Pseudomonas spp. (8.07%), Enterobacter spp. (2.3%), other Gram-negative bacteria (2.3%), and other Gram-positive bacteria (3.45%). High antibiotic resistance was detected for ampicillin, amoxicillin, and second-generation cephalosporins. Escherichia coli presented high resistance for cefepime and ceftriaxone. Pseudomonas spp. remained susceptible to amikacin, quinolones, and colistin. Vancomycin, teicoplanin, linezolid, and piperacillin/tazobactam remained effective in treating Gram-positive UTI. Conclusions: High antibiotic resistance was identified for frequently used antibiotics. Lower antibiotic resistance was observed for some broad-spectrum antibiotics. Understanding uropathogens’ antibiotic resistance is important in creating treatment recommendations, based on international guidelines, local resistance patterns, and patient particularities

    Prognosis Communication in Pediatric Oncology: A Systematic Review

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    Background: While communication plays an important role in medicine, it also often represents a challenge when the topic at hand is the prognosis of a high-risk condition. When it comes to pediatric oncology, the challenge becomes even greater for physicians who have to adapt their discourse to both the child and their family. Methods: Following the PRISMA guidelines, an advanced search on PubMed, Scopus and the Cochrane Library was performed, from 1 January 2017 to 31 October 2022. Demographic data for caregivers, pediatric patients and physicians were extracted, as well as diagnosis, prognosis, presence at discussion, emotional states and impact on life, trust, decision roles, communication quality and other outcomes. Results: A total of 21 articles were analyzed. Most studies (17) focused on caregivers, while only seven and five studies were focused on children and physicians, respectively. Most parents reported high trust in their physicians (73.01%), taking the leading role in decision making (48%), moderate distress levels (46.68%), a strong desire for more information (78.64%), receiving high-quality information (56.71%) and communication (52.73%). Most children were not present at discussions (63.98%); however, their desire to know more was expressed in three studies. Moreover, only two studies observed children being involved in decision making. Most physicians had less than 20 years of experience (55.02%) and reported the use of both words and statistics (47.3%) as a communication method. Conclusions: Communication research is focused more on caregivers, yet children may understand more than they seem capable of and want to be included in the conversation. More studies should focus on and quantify the opinions of children and their physicians. In order to improve the quality of communication, healthcare workers should receive professional training
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