Search

Hg 1 − x Cd x Te alloys are unique because by increasing the Cd content x, one modifies the band structure from inverted to normal, which fundamentally modifies the dispersion of bulk, surface or edge (in the case of quantum wells) energy states. Using alloys with x close to the concentration xc at which the band inversion transition is observed and with additional application of hydrostatic pressure (p), one creates a favorable playground for studying the evolution of Dirac matter and its topological properties. In this work, cryogenic magnetospectroscopy in quantizing magnetic fields (B) in the far-infrared is used to study inter-Landau-level transitions in high-quality Hg 1 − x Cd x Te MBE-grown epitaxial layers with x ≈ x c as a function of p up to 4.2 kbar. Special attention is paid to elucidate the role of the substrate and buffer layers, which usually modify the pressure coefficients of epitaxial layers. For this purpose, comparative measurements were carried out on as-grown epilayers with a GaAs substrate and on free-standing layers obtained by etching off the substrate. Spectra registered as a function of B (at given p) were analyzed with the help of the Kane model modified to include magnetic field. The pressure coefficient as well as the difference between conduction and valence band deformation potentials of the free-standing layer were determined at 2 K. Surprisingly, the deformation potentials and pressure coefficients of the epitaxial layer and those of the free-standing layer differed by no more than 10% in the pressure range up to 4.2 kbar. This finding questions the common belief of a dominant influence of the substrate on the pressure coefficients of epitaxial layers. We attribute the smallness of this difference to the presence of a highly disordered CdTe buffer separating the substrate from the epitaxial layer, which relaxes the transmission of strain from the substrate to the layer. Our results contribute to a better understanding of pressure experiments carried out on epitaxial layers on a substrate. [ABSTRACT FROM AUTHOR]

Cristina O Daia,1,2 Monica Haras,1,2 Tiberiu Spircu,1 Aurelian Anghelescu,1,2 Liliana Onose,3 Alexandru Vlad Ciurea,1,2 Anca Sanda Mihaescu,2 Gelu Onose1,21Carol Davila University of Medicine and Pharmacy, Bucharest, Romania; 2Bagdasar-Arseni Teaching Emergency Hospital, Bucharest, Romania; 3Metrorex – The Medical Service, Bucharest, RomaniaBackground: Neuroprotection is a modern therapeutic concept that has some useful outcomes discussed in the literature, including for traumatic brain injury (TBI).Scope and study design: This was a retrospective case-control study that was approved by the bioethics commission of the Bagdasar-Arseni Teaching Emergency Hospital, Bucharest, Romania. The aim of the study was to comparatively assess neurorestorative, including neurorehabilitative, outcomes obtained with or without Cerebrolysin®.Materials and methods: Nineteen cases treated with Cerebrolysin versus 28 who did not receive this drug were included in this study. All cases had a subacute or post-acute status after TBI and were hospitalized (only at their first admission) between January 2005 and December 2010 in the hospital's NeuroRehabilitation Clinic Division. Epidemiological, clinical, paraclinical, and functional parameters were evaluated, using the: Functional Independence Measure (FIMTM), Glasgow Outcome Score (GOS), and Modified Rankin Scale.Results: Patients in the Cerebrolysin group had, on average, higher (although not statistically significant) FIM evolution values (36.53) than the control group (29.64) (P=0.174, 95% confidence interval: -8.0 to 21.8). The effect size assessed on the GOS was 2.1%. Additionally, the mean FIM value at admission of the Cerebrolysin group (45.79) was lower than that of controls (61.50; P=0.076).Discussion and conclusion: The clinical/functional evolution, comparatively evaluated in the studied inpatients, and taking into account the small sample and effect sizes – including for GOS – suggest that Cerebrolysin, correctly indicated and administered, may perhaps contribute to some improvement of post-TBI patients' overall neurorestorative/rehabilitative outcomes; this given the short period (approximately 1 month) over which the medicine's action was evaluated, the lower FIM mean value at admission in the Cerebrolysin group, and respectively that, for severe central nervous system lesions – including after TBI – and consequent conditions, it cannot yet be concluded that any therapeutic approaches, such as Cerebrolysin, can significantly improve post-injury outcomes.Keywords: neuroprotection, Functional Independence Measure (FIM), brain trauma

Lignin graft copolymer (LGC) was prepared using an addition polymerization technique that involved grafting a 2-acrylamido-2- methylpropane sulfonic acid (AMPS) monomer onto soda lignin (SL). The optimal polymerization conditions were found to be as follows: soda lignin, 2.0 g; initiator, 3% (w/w) potassium persulphate of SL; mass ratio of AMPS to SL, 1:2; reaction time, 7 h; and reaction temperature, 60 °C. The LGC was characterized using a Fourier transform infrared (FTIR) spectroscopy, a thermogravimetric analyzer (TGA), and gel permeation chromatography (GPC). The filtrate loss controlling ability of the LGC was evaluated using the American Petroleum Institute Recommended Practice 13-B 1 standard procedures. The results showed that the LGC has remarkable rheological and filtration controlling properties at both room temperature and high aging temperatures (190 °C). [ABSTRACT FROM AUTHOR]

The article explores the concept of quality of life, nature of aging and factors affecting it. The definition of health by the World Health Organization (WHO) is used to explain wellness in all facets of life. The increase of the elderly population necessitates a new approach to healthcare including the promotion of socially active lifestyle. The role of physical and rehabilitation medicine in contributing to a good quality of life is also discussed.

Nail-patella syndrome, also known as hereditary onycho-osteodystrophy, is a rare autosomal dominant disorder with pleiotropic phenotypic expression. The present report is of a nail-patella syndrome patient, a 26-year-old female, admitted to our NeuroMuscular Rehabilitation Clinic Division for neurological symptoms, secondary to a severe spondylolysthesis with bilateral L5 pedicle fracture. During hospitalization, she was also diagnosed with mild thyrotoxicosis, but interestingly enough, the bone mineral density, assessed at multiple sites, was quasi-normal. [ABSTRACT FROM AUTHOR]

Background: The last two decades have come up with some important progresses in the genetic, immune, histochemical and bio (nano)-technological domains, that have provided new insight into cellular/ molecular mechanisms, occurring in the central nervous system (CNS) - including in spinal cord - injuries. Methods: In previous works, emerging from our theoretical and practical endeavors in the field, we have thoroughly described the principal intimate propensity and the pathophysiological processes - representing intrinsic limitations for self-recovery after SCI, and, at the same time, subtle targets for neuroprotection/ recovery - and reviewed the main related worldwide-published reports. The aim of this paper is to emphasize the connections between such main aspects and some feasible integrative solutions, including the ones for clinical practice. Results: Consequently, we stress upon some therapeutic suggestions regarding this subject matter by systematizing the most up to date and efficient ones - obviously, within major limits, according to the very low capacities of CNS/ spinal cord (SC) to post-injury self preserve and recover. Moreover, we also talk about accessible drugs, respectively those being already in clinical use (but at present, mainly used to treat other conditions, including the neurological ones) and hence, with relatively well known, determined effects and/or respectively, restrictions. Discussions: The recent advances in the knowledge on the basic components of the afore mentioned CNS/ SC propensity for self destroying and inefficient endogenous repair mechanisms in the actual new context, will hopefully be, from now on, more effectively correlated with revolutionary - mostly still experimental - treatments, especially by using stem cells within tissue engineering, including, if needed, more advanced/ courageous approaches, based on somatic cell nuclear transfer (SCNT). Conclusions: This paper contains the scientific motivated highlighting of some already available drugs, "neuroprotective" (and not only) properties too, which enable practitioners with (although not yet capable to cure - but anyway) more efficient therapeutic means, to approach the extremely difficult and still painfully disappointing domain, of spinal cord injury (SCI). [ABSTRACT FROM AUTHOR]

Background: Discovery of neurotrophic factors - emblematic: the nerve growth factor (NGF) - resulted in better approaching central nervous system (CNS) lesions. Recently, another crucial property has been unveiled: their rather unique pleiotropic effect. Cerebrolysin is a peptide mixture that penetrates the blood-brain barrier in significant amounts and mimics the effects of NGF. Methods: Comparative analysis: Cerebrolysin treated (10 ml x 2/ day, i.v. x 3 weeks) vs. non-treated, in patients (all received aside, a rather equivalent complementary, pharmacological and physical, therapy). Two lots of patients, admitted in our Physical & Rehabilitation (neural-muscular) Medical - PR(n-m)M - Clinic Division, during 2007-2009: 69 treated with Cerebrolysin (22 F, 47 M; Average: 59.333; Mean of age: 61.0 Years old; Standard deviation 16.583) and 70 controls (41 F, 29 M; A: 70.014; M.o.a.: 70.5 Y.o.; S.d.: 6.270) were studied. The total number of assessed items was 13: most contributive in relation with the score of Functional Independence Measure at discharge (d FIM), were: admission (a FIM), number of physical therapy days (PT), number of hospitalization days (H), age (A) and - relatively - days until the first knee functional extension (KE). Concomitantly, the main/ key, focused on neuro-motor rehabilitative outcomes, functional/analytical parameters, have been assessed regarding the speed in achieving their functional recovery. Results: Concerning d FIM, there have not been objectified significant differences between the two lots (p=0.2453) but regarding key, focused on neuro-motor rehabilitative outcomes, functional/analytical parameters: KE (p=0.0007) and days until the first time recovery of the ability to walk between parallel bars (WPB - p=0.0000) - highly significant differences in favor of Cerebrolysin lot resulted. Conclusion: Cerebrolysin administration, as neurorehabilitative outcomes, proved to hasten, statistically significant, especially the recovery of some critical, for standing and walking, parameters. Thus encouraged, we have now initiated a comprehensive national, 5 year retrospective, multi-centre - based on unitary data acquisition frame and mathematical apparatus - study, to evaluate the results of the treatment with Cerebrolysin in traumatic brain injuries (TBI). [ABSTRACT FROM AUTHOR]

The current global financial crisis inevitably alters the quality of life (QoL) of many individuals, mainly (but not exclusively) concerning its fourth -- after Guelfi -- dimension: the economic one (a deeply intricate component). Under these conditions, we can only hope that the holistic and idealistic definition of health, adopted by the World Health Organization (WHO) almost 70 years ago, will keep its topicality and applicability -- as before the recession -- at least in the more developed countries/ economies. This work presents a synthetic overview on some basic issues regarding health and related QoL, focusing on their connections with the specialties of Physical & Rehabilitation Medicine and respectively, Gerontology & Geriatrics: the presence/ absence of risk factors, (especially) the ones associated to the "civilization pathology", wellness, the current thinking/ paradigm (integrating the medical and social models) of the WHO on human functioning, (di)stress -- including its relationship to premature/ pathologic ageing -- and the active prophylactic (relaxing, fitness/"mise en forme"/ anti-stress, maintaining/ re-performing of the work capacity, rejuvenation/ anti-ageing/ gero-prophylaxis) balneo-climatic courses. The construct and content of this work are framed within the very actual, leading specific concepts and outcome measurement indicators of the European Union, regarding the major global challenge represented by the accelerated demographic ageing process [and consequent endeavors, such as the European Innovation Partnership on Active and Healthy Ageing (EIPAHA), and also a most recent project/ surveys -- for doctors and for 60+ older adult patients -- of the main author and some colleagues -- endorsed by the Comité Permanent/ Standing Committee of the European Doctors (CPME) -- regarding "Health Literacy on Functional Decline and Frailty Related to Ageing" and respectively, the Healthy Life Years (HLY) and disability-adjusted life years (DALY) -- synthetic health state (macro-)indicators. Considering all above, this work documents/ ratiocinate and advocates for Romania's huge capabilities of health tourism -- its balneo-geriatric, consistent dimension -- too. [ABSTRACT FROM AUTHOR]

Hg 1- x Cd x Te is a unique material with its bandgap being tunable by temperature, pressure, and cadmium content over a wide range, from 1.6 eV to an inverted bandgap of -0.3 eV. This makes Hg 1- x Cd x Te one of the key materials for infrared and terahertz detectors, whose characteristics largely depend on the material's noise properties. In this work, we investigated the low-frequency 1/ f noise in a thick (800 nm) HgCdTe layer and in a field effect transistor (FET) with an 8 nm wide HgTe quantum well. Both structures exhibited a small contribution from contact noise and showed weak noise dependences on temperature. Investigation of the 1/ f noise in the HgTe quantum well FET as a function of gate voltage revealed that the noise also depends weakly on electron concentration. These findings indicate that the noise properties of Hg 1- x Cd x Te are similar to those of graphene, where mobility fluctuations were found to be the dominant mechanism of the 1/ f noise.

Recent development of terahertz systems has created the need for new elements operating in this frequency band, i.e. , fast tunable devices such as varactors. Here, we present the process flow and characterization of a novel electronic variable capacitor device that is made with the use of 2D metamaterials such as graphene (GR) or hexagonal boron nitride (h-BN). Comb-like structures are etched into a silicon/silicon nitride substrate and a metal electrode is deposited at the bottom. Next, a PMMA/GR/h-BN layer is placed on top of the sample. As voltage is applied between GR and metal, the PMMA/GR/h-BN layer bends towards the bottom electrode thus decreasing the distance between electrodes and changing the capacitance. The high tunability and complementary metal oxide semiconductor (CMOS)-compatible process flow of the platform for our device and its millimeter size make it promising for applications in future electronics and terahertz technologies. The goal of our research is to integrate our device with dielectric rod waveguides, thus making THz phase shifters.

The gas sensing properties of graphene back-gated field-effect transistor (GFET) sensors toward acetonitrile, tetrahydrofuran, and chloroform vapors were investigated with the focus on unfolding possible gas detection mechanisms. The FET configuration of the sensor device enabled gate voltage tuning for enhanced measurements of changes in DC electrical characteristics. Electrical measurements were combined with a fluctuation-enhanced sensing methodology and intermittent UV irradiation. Distinctly different features in 1/ f noise spectra for the organic gases measured under UV irradiation and in the dark were observed. The most intense response observed for tetrahydrofuran prompted the decomposition of the DC characteristic, revealing the photoconductive and photogating effect occurring in the graphene channel with the dominance of the latter. Our observations shed light on understanding surface processes at the interface between graphene and volatile organic compounds for graphene-based sensors in ambient conditions that yield enhanced sensitivity and selectivity.

In this work we demonstrated the process of co-deposition of copper-tin sulfide species by the atomic layer deposition (ALD) technique using all-low-cost precursors. For the deposition of tin species, the tin(IV) chloride SnCl 4 was used successfully for the first time in the ALD process. Moreover, we showed that the successful deposition of the tin sulfide component was conditioned by the pre-deposition of CuS x layer. The co-deposition of copper and tin sulfides components at 150 °C resulted in the in-process formation of the film containing Cu 2 SnS 3 , Cu 3 SnS 4 and π -SnS phases. The process involving only tin precursor and H 2 S did not produce the SnS x species. The spectroscopic characteristic of the obtained materials were confronted with the literature survey, allowing us to discuss the methodology of the determination of ternary and quaternary sulfides purity by Raman spectroscopy. Moreover, the material characterisation with respect to the morphology (SEM), phase composition (XRD), surface chemical states (XPS), optical properties (UV-vis-NIR spectroscopy) and electric (Hall measurements) properties were provided. Finally, the obtained material was used for the formation of the p-n junction revealing the rectifying I - V characteristics., (© 2022 IOP Publishing Ltd.)

Recently, an unprecedented growth in the internet of things (IoT) is being observed, which is becoming the main driver for the entire semiconductor industry. Reliable maintenance and servicing of the IoT is becoming challenging, knowing that the IoT nodes outnumber the human population by a factor of seven. Energy harvesting (EH) can overcome those difficulties, delivering the energyautonomous IoT nodes to the market. EH converts natural or waste energies (vibrations, heat losses, air flows, light, etc.) into useful energy. This article explores the performance of ZnO nanowires under mechanical actuation to characterize their piezoelectric performance. ZnO nanowires were fabricated using ALD and a subsequent chemical bath growth. AISI 301 steel was used as a substrate of the EH device to better fit the mechanical requirements for the piezoelectric generator. We determined that a thin layer of another oxide below ZnO provides outstanding adhesion. The samples were submitted under repetitive mechanical stress in order to characterize the output piezovoltage for different conditions. They exhibited a piezoelectric signal which was stable after hundreds of actuations. This shows good promise for the use of our device based on ZnO, an Earth-abundant and non-toxic material, as an alternative to the conventional and popular but harmful and toxic PZT. The designed measurement setup demonstrated that a AISI 301 steel substrate coated with ZnO deposited by ALD and grown in a chemical bath has promising performance as a piezoelectric material. Characterized ZnO samples generate up to 80 nJ of energy during 55 s runs under matched load conditions, which is sufficient to supply a modern IoT node.

Objective: To assess the impact of socio-demographic and comorbidity factors, and quantified depressive symptoms on disability in inpatients., Methods: Observational cross-sectional study, including a number of 80 elderly (16 men, 64 women; mean age 72.48 years; standard deviation 9.95 years) admitted in the Geriatrics Clinic of "St. Luca" Hospital, Bucharest, between May-July, 2012. We used the Functional Independence Measure, Geriatric Depression Scale and an array of socio-demographic and poly-pathology parameters. Statistical analysis included Wilcoxon and Kruskal-Wallis tests for ordinal variables, linear bivariate correlations, general linear model analysis, ANOVA., Results: FIM scores were negatively correlated with age (R=-0.301; 95%CI=-0.439 -0.163; p=0.007); GDS scores had a statistically significant negative correlation (R=-0.322; 95% CI=-0.324 -0.052; p=0.004) with FIM scores. A general linear model, including other variables (gender, age, provenance, matrimonial state, living conditions, education, respectively number of chronic illnesses) as factors, found living conditions (p=0.027) and the combination of matrimonial state and gender (p=0.004) to significantly influence FIM scores. ANOVA showed significant differences in FIM scores stratified by the number of chronic diseases (p=0.035)., Discussion and Conclusions: Our study objectified the negative impact of depression on functional status; interestingly, education had no influence on FIM scores; living conditions and a combination of matrimonial state and gender had an important impact: patients with living spouses showed better functional scores than divorced/widowers; the number of chronic diseases also affected the FIM scores: lower in patients with significant polypathology. These findings should be considered when designing geriatric rehabilitation programs, especially for home--including skilled--cares.

Background: The last two decades have come up with some important progresses in the genetic, immune, histochemical and bio (nano)-technological domains, that have provided new insight into cellular/molecular mechanisms, occurring in the central nervous system (CNS)--including in spinal cord-injuries., Methods: In previous works, emerging from our theoretical and practical endeavors in the field, we have thoroughly described the principal intimate propensity and the pathophysiological processes--representing intrinsic limitations for self-recovery after SCI, and, at the same time, subtle targets for neuroprotection/recovery--and reviewed the main related worldwide-published reports. The aim of this paper is to emphasize the connections between such main aspects and some feasible integrative solutions, including the ones for clinical practice., Results: Consequently, we stress upon some therapeutic suggestions regarding this subject matter by systematizing the most up to date and efficient ones--obviously, within major limits, according to the very low capacities of CNS/ spinal cord (SC) to post-injury self preserve and recover. Moreover, we also talk about accessible drugs, respectively those being already in clinical use (but at present, mainly used to treat other conditions, including the neurological ones) and hence, with relatively well known, determined effects and/or respectively, restrictions., Discussions: The recent advances in the knowledge on the basic components of the afore mentioned CNS/ SC propensity for self destroying and inefficient endogenous repair mechanisms in the actual new context, will hopefully be, from now on, more effectively correlated with revolutionary--mostly still experimental--treatments, especially by using stem cells within tissue engineering, including, if needed, more advanced/courageous approaches, based on somatic cell nuclear transfer (SCNT)., Conclusions: This paper contains the scientific motivated highlighting of some already available drugs, "neuroprotective" (and not only) properties too, which enable practitioners with (although not yet capable to cure--but anyway) more efficient therapeutic means, to approach the extremely difficult and still painfully disappointing domain, of spinal cord injury (SCI).