Investigating the physical and optoelectronic characteristics of Co2ZrZ compounds: findings from computational analysis and thermoelectric evaluation

CONTEXT AND RESULTS

The study examines the physical characteristics of Co2ZrZ compounds using the Wien2k code and the Anisimov and Gunnarsson approach. Results show metallic attributes in Co2ZrBi and Co2ZrAs, while Co2ZrPb exhibits semi-metallic tendencies. Energy gap evaluations reveal significant infrared transitions, indicating altered electron mobility compensated by increased ultraviolet absorption. These compounds have potential in space solar energy applications due to UV light absorption capabilities, especially in Co2ZrPb. The study also identifies optical phenomena like "super-luminescence" and plasmatic oscillations.

COMPUTATIONAL AND THEORETICAL TECHNIQUES

The study uses computational techniques like Wien2k calculation code and Hubbard parameter calculations to investigate Co2ZrPb, a compound with potential for space energy applications. Energy gap assessments are conducted using GGA and mBJ-GGA methods. The study also analyzes the optical behavior of the compounds, including infrared and ultraviolet absorption. The BoltzTraP code is used for thermoelectric investigations, revealing a P-type charge carrier predominance in Co2ZrPb. This comprehensive approach provides valuable insights into electrical conductivity and thermoelectric properties.

Virucidal activity of oral, hand, and surface disinfectants against respiratory syncytial virus

BACKGROUND

Respiratory syncytial virus (RSV) is known as a major cause of respiratory tract infection in adults and children. Human-to-human transmission occurs via droplets as well as direct and indirect contact (e.g. contaminated surfaces or hands of medical staff). Therefore, applicable hygiene measures and knowledge about viral inactivation are of utmost importance.

AIM

To elucidate the disinfection profile of RSV.

METHODS

The study evaluated the virucidal efficacy of oral rinses specifically designed for children, World Health Organization (WHO)-recommended hand-rub formulations, and ethanol, as well as 2-propanol against RSV in a quantitative suspension test (EN14476). The stability of RSV on stainless steel discs was assessed and its inactivation by different surface disinfectants (EN16777) investigated.

FINDINGS

All tested oral rinses except one reduced infectious viral titres to the lower limit of quantification. The two WHO-recommended hand-rub formulations as well as 30% ethanol and 2-propanol completely abolished the detection of infectious virus. Infectious RSV was recovered after several days on stainless steel discs. However, RSV was efficiently inactivated by all tested surface disinfectants based on alcohol, aldehyde, or hydrogen peroxide.

CONCLUSION

Oral rinses, all tested hand-rub formulations as well as surface inactivation reagents were sufficient for RSV inactivation in vitro.

AB1340 PREVALENCE OF THE WRISTS AND HANDS SYNOVITIS IN SUBGROUPS OF PATIENTS FOLLOWED FOR SYSTEMIC LUPUS ERYTHEMATOSUS

Background

Joint damage is one of the most common manifestations of SLE. Represented by the presence of arthralgia or arthritis, with or without deformities or erosions.

Musculoskeletal ultrasound allows evaluation of the inflammatory joint damage for more targeted therapeutic approach.

Objectives

The aim of this study was to estimate the prevalence of the wrists and hands synovitis (WHS) in subgroups of patients with systemic lupus erythematosus (SLE) and to compare them with each other.

Methods

One hundred and sixty-nine patients with SLE were consecutively recruited in the rheumatology unit (consultation or hospitalization) of the Ben Aknoun hospital, Algiers-Algeria. Stratification into subgroups was carried out: non-deforming non-destructive patients (NDND), rhupus patients (if coexistence of lupus and rheumatoid arthritis criteria), patients with moderate deforming arthropathy (MDA) or Jaccoud arthropathy according to the score of the Spronk index.

For each patient, demographic data, duration of SLE evolution and joint involvement were collected, a standard inflammatory biology report and screening for rheumatoid factor (RF) and anti-CCP (ACPA) were requested.

A musculoskeletal ultrasound of the wrists, MCP and PIP (from the 2nd to the 5th rays) was performed with a search for synovitis and erosions, the ultrasound examination was preceded by the calculation of the SLEDAI score and the HAQ score.

Results

169 patients were recruited: 135 NDND, 18 rhupus, 10 Jaccoud, 6 MDA, respective mean age of 38.38 ± 11.79, 39.39 ± 11.74, 41.10 ± 9.5, 47 ± 9.35 years. The mean duration of lupus was 8.23 ​​± 6.97, 12.33 ± 8.71, 13.10 ± 6.6 and 15 ± 5.93 years, respectively. The mean duration of joint involvement was 7.38 ± 6.920, 12.22 ± 8.84, 13.10 ± 6.6, 15 ± 5.93 years. The positive CRP was found respectively in 20%, 38.9%, 20%, and 16.7%.

The frequency of WHS, RF, ACPA and erosions was significantly higher in the rhupus group compared to that of NDND (p <0.001). No difference in mean SLEDAI scores between subgroups. The mean HAQ score was higher in patients in the rhupus and Jaccoud groups compared to the mean score in patients in the NDND and MDA group (p <0.0001).

Conclusion

Our results confirm that rhupus patients have more inflammatory and erosive involvement than other lupus subgroups. It represents an overlap between rheumatoid arthritis and lupus more than a separate entity. We have also shown that deforming arthropathies without structural damage correspond to a late course in a group of patients initially non-deforming non-destructive.

References

[1]Mosca M, Tani C, Carli L, Vagnani S, Possemato N, Delle Sedie A, et al. The role of imaging in the evaluation of joint involvement in 102 consecutive patients with systemic lupus erythematosus. Autoimmun Rev. 2015;14(1):10–15.

[2]Gabba A, Piga M, Vacca A, Porru G, Garau P, Cauli A, et al. Joint and tendon involvement in systemic lupus erythematosus: an ultrasound study of hands and wrists in 108 patients. Rheumatology. 2012;51(12):2278–2285.

[3]Salliot C, Denis A, Dernis E, Andre V, Perdriger A, Albert J-D, et al. Ultrasonography and detection of subclinical joints and tendons involvements in Systemic Lupus erythematosus (SLE) patients: A cross-sectional multicenter study. Joint Bone Spine. 2018;85(6):741–745.

Disclosure of Interests

None declared

[Results of vacuum sealing therapy in joint infections]

AIM

At present the vacuum sealing technique is acknowledged as a therapy for acute and chronic wounds. An acceleration of the healing process, due to the vacuum suction with occlusive wound dressing, leads to the shortening of a cost-effective medical treatment. This can be applied to wound treatment and infections of soft tissues, but even today there is only sparse information in this context about joint infections.

METHOD

The results of therapy with the vacuum sealing technique in 68 patients with infections of the joints of an extremity or the trunk were analysed in a retrospective study without a control group. The importance of several patient-related factors for the medical treatment have been analysed.

RESULTS

An adequate treatment of joint infections can be achieved even in the presence of endoprostheses or osteosynthetic material. The following factors have been found to be of significance for a prolonged medical treatment: diabetes mellitus (p=0.0052), obesity (BMI>25) (p=0.0458) and a preceding trauma (p=0.0457).

CONCLUSION

The results confirm the value of the vacuum sealing technique following surgical debridement in combination with resistance tested antibiotic treatment, as a sufficient therapy for joint infections, even in patients with an endoprosthesis. This procedure leads to a safe treatment of the joint infection, combined with a good function of the treated joint, good patient comfort and a short duration of the therapy.

Sensitivity to MPTP is not increased in Parkinson's disease-associated mutant alpha-synuclein transgenic mice

Environmental and genetic factors that contribute to the pathogenesis of Parkinson's disease are discussed. Mutations in the alpha-synuclein (alphaSYN ) gene are associated with rare cases of autosomal-dominant Parkinson's disease. We have analysed the dopaminergic system in transgenic mouse lines that expressed mutant [A30P]alphaSYN under the control of a neurone-specific Thy-1 or a tyrosine hydroxylase (TH) promoter. The latter mice showed somal and neuritic accumulation of transgenic [A30P]alphaSYN in TH-positive neurones in the substantia nigra. However, there was no difference in the number of TH-positive neurones in the substantia nigra and the concentrations of catecholamines in the striatum between these transgenic mice and non-transgenic littermates. To investigate whether forced expression of [A30P]alphaSYN increased the sensitivity to putative environmental factors we subjected transgenic mice to a chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) regimen. The MPTP-induced decrease in the number of TH-positive neurones in the substantia nigra and the concentrations of catecholamines in the striatum did not differ in any of the [A30P]alphaSYN transgenic mouse lines compared with wild-type controls. These results suggest that mutations and forced expression of alphaSYN are not likely to increase the susceptibility to environmental toxins in vivo.

Protection by synergistic effects of adenovirus-mediated X-chromosome-linked inhibitor of apoptosis and glial cell line-derived neurotrophic factor gene transfer in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces clinical, biochemical, and neuropathological changes reminiscent of those occurring in idiopathic Parkinson's disease (PD). Here we show that a peptide caspase inhibitor, N-benzyloxy-carbonyl-val-ala-asp-fluoromethyl ketone, or adenoviral gene transfer (AdV) of a protein caspase inhibitor, X-chromosome-linked inhibitor of apoptosis (XIAP), prevent cell death of dopaminergic substantia nigra pars compacta (SNpc) neurons induced by MPTP or its active metabolite 1-methyl-4-phenylpyridinium in vitro and in vivo. Because the MPTP-induced decrease in striatal concentrations of dopamine and its metabolites does not differ between AdV-XIAP- and control vector-treated mice, this protection is not associated with a preservation of nigrostriatal terminals. In contrast, the combination of adenoviral gene transfer of XIAP and of the glial cell line-derived neurotrophic factor to the striatum provides synergistic effects, rescuing dopaminergic SNpc neurons from cell death and maintaining their nigrostriatal terminals. These data suggest that a combination of a caspase inhibitor, which blocks death, and a neurotrophic factor, which promotes the specific function of the rescued neurons, may be a promising strategy for the treatment of PD.

Deficiency of inducible nitric oxide synthase protects against MPTP toxicity in vivo

MPTP produces clinical, biochemical, and neuropathologic changes reminiscent of those that occur in idiopathic Parkinson's disease (PD). In the present study we show that MPTP treatment led to activation of microglia in the substantia nigra pars compacta (SNpc), which was associated and colocalized with an increase in inducible nitric oxide synthase (iNOS) expression. In iNOS-deficient mice the increase of iNOS expression but not the activation of microglia was blocked. Dopaminergic SNpc neurons of iNOS-deficient mice were almost completely protected from MPTP toxicity in a chronic paradigm of MPTP toxicity. Because the MPTP-induced decrease in striatal concentrations of dopamine and its metabolites did not differ between iNOS-deficient mice and their wild-type littermates, this protection was not associated with a preservation of nigrostriatal terminals. Our results suggest that iNOS-derived nitric oxide produced in microglia plays an important role in the death of dopaminergic neurons but that other mechanisms contribute to the loss of dopaminergic terminals in MPTP neurotoxicity. We conclude that inhibition of iNOS may be a promising target for the treatment of PD.

MPP+ inhibits proliferation of PC12 cells by a p21(WAF1/Cip1)-dependent pathway and induces cell death in cells lacking p21(WAF1/Cip1)

The molecular and biochemical mode of cell death of dopaminergic neurons in Parkinson's disease (PD) is uncertain. In an attempt at further clarification we studied the effects of 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), on dopaminergic PC12 cells. In humans and nonhuman primates MPTP/MPP+ causes a syndrome closely resembling PD. MPP+ toxicity is thought to be mediated by the block of complex I of the mitochondrial electron transport chain. Treatment of undifferentiated PC12 cells with MPP+ primarily inhibited proliferation of PC12 cells and secondarily led to cell death after the depletion of all energy substrates by glycolysis. This cell death showed no morphological characteristics of apoptosis and was not blocked by treatment with caspase inhibitors. The inhibition of cell growth was not dependent on an inhibition of complex I activity since MPP+ also inhibited cell proliferation in SH-SY5Y cells lacking mitochondrial DNA and complex I activity (p0 cells). As shown by flow cytometric analysis, MPP+ induced a block in the G0/G1 to S phase transition that correlated with increased expression of the cyclin-dependent kinase inhibitor p21(WAF1/Cip1) and growth arrest. Since treatment with 1 microM MPP+ caused apoptotic cell death in p21(WAF1/Cip1)-deficient (p21(-/-)) but not in parental (p21(+/+)) mouse embryo fibroblasts, our data suggest that in an early phase MPP+-induced p21(WAF1/Cip1) expression leads to growth arrest and prevents apoptosis until energy depletion finally leads to a nonapoptotic cell death.

Femoral artery laceration complicating an intertrochanteric hip fracture: a multi-disciplinary therapeutic problem

Major arterial injuries are uncommon complications of intertrochanteric hip fractures. Described is transcatheter embolization of a lacerated femoral artery complicated by a large hematoma, discovered following surgical repair of an eight day old intertrochanteric fracture. The case was complicated due to a history of aspirin usage, marked obesity, and thrombocytopenia. Interventional radiology techniques may provide an alternative to surgery in selected cases.