High Sodium Ion Storage by Multifunctional Covalent Organic Frameworks for Sustainable Sodium Batteries

Rechargeable sodium batteries hold great promise for circumventing the increasing demand for lithium-ion batteries (LIBs) and the limited supply of lithium. However, efficient sodium ion storage remains a great impediment in this field. In this study, we report the designed synthesis of a multifunctional two-dimensional covalent organic framework featuring hexaazatrinaphthalene cores linked by imidazole moieties and demonstrate its effective performance in sodium ion storage. Benzimidazole-linked covalent organic framework (BCOF-1) was synthesized by a condensation reaction between hexaazatrinaphthalenehexamine (HATNHA) and terephthalaldehyde (TA) and exhibited a high theoretical specific capacity of 392 mA h g-1. BCOF-1 crystallizes, forming eclipsed AA stacking and mesoporous hexagonal one-dimensional channels with high surface area (840 m2 g-1), facilitating fast ionic mobility and charge transfer and enabling high-rate capability at high current rates. BCOF-1 exhibits pseudocapacitive-like behavior with a high specific capacity of 387 mA h g-1, an energy density of 302 W h kg-1 at 0.1 C, and a power density of 682 W kg-1 at 5 C. Our results demonstrate that redox-active COFs have the desired structural and electronic merits to advance the use of organic electrodes in sodium-ion storage toward sustainable and efficient batteries.

The contribution of cooking appliances and residential traffic proximity to aerosol personal exposure

PURPOSE

Indoor and outdoor factors affect personal exposure to air pollutants. Type of cooking appliance (i.e. gas, electricity), and residential location related to traffic are such factors. This research aims to investigate the effect of cooking with gas and electric appliances, as an indoor source of aerosols, and residential traffic as outdoor sources, on personal exposures to particulate matter with an aerodynamic diameter lower than 2.5 μm (PM_2.5), black carbon (BC), and ultrafine particles (UFP).

METHODS

Forty subjects were sampled for four consecutive days measuring personal exposures to three aerosol pollutants, namely PM_2.5, BC, and UFP, which were measured using personal sensors. Subjects were equally distributed into four categories according to the use of gas or electric stoves for cooking, and to residential traffic (i.e. houses located near or away from busy roads).

RESULTS/CONCLUSION

Cooking was identified as an indoor activity affecting exposure to aerosols, with mean concentrations during cooking ranging 24.7-50.0 μg/m³ (PM_2.5), 1.8-4.9 μg/m³ (BC), and 1.4 × 10⁴-4.1 × 10⁴ particles/cm³ (UFP). This study also suggest that traffic is a dominant source of exposure to BC, since people living near busy roads are exposed to higher BC concentrations than those living further away from traffic. In contrast, the contribution of indoor sources to personal exposure to PM_2.5 and UFP seems to be greater than from outdoor traffic sources. This is probably related to a combination of the type of building construction and a varying range of activities conducted indoors. It is recommended to ensure a good ventilation during cooking to minimize exposure to cooking aerosols.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40201-020-00604-7.

ROBERTS SYNDROME: CLINICAL AND CYTOGENETIC STUDIES IN 8 EGYPTIAN PATIENTS AND MOLECULAR STUDIES IN 4 PATIENTS WITH GENOTYPE/PHENOTYPE CORRELATION

The Roberts syndrome (RBS) is a rare autosomal recessive disorder caused by mutation in ESCO2 gene. Among over 150 reported international cases, 16 cases are Egyptian including the presently reported patients. The current study reports 8 new Egyptian patients from 7 unrelated consanguineous families investigating clinical phenotype as well as cytogenetic changes in all cases and mutational spectrum in 4 cases. Clinical, orodental, cytogenetic and molecular studies were done to investigate genotype/phenotype correlation. Evaluation of the studied 8 patients showed that they all exhibited the main limb and craniofacial features of Roberts syndrome. Cytogenetic studies including centromeric separation and puffing by Giemsa and DAPI stains and for the first time in Egypt analysis for premature centromeric division by FISH showed consistent centromeric separation in all studied cases. Molecular studies of 4 available patients showed that they all have ESCO2 gene mutation. We conclude that RBS has a well-defined clinical spectrum. The cytogenetic changes are due to sister chromatid cohesion defects which lead to mitotic dysfunction. We confirmed previous results of lack of genotype/phenotype correlation. We also confirmed that the severity of limb malformation correlates with craniofacial manifestations. We recommend detailed evaluation of orodental changes for further definition of the phenotype and for proper patient management. We emphasize the need for further studies for the frequency of premature centromeric separation by FISH as a possible indicator of phenotypic severity.

Role of ureteric stents in relieving obstruction in patients with obstructive uropathy

Purpose:

The aim of this study is to evaluate the role of ureteric stents in relieving obstruction and improvement of kidney function in patients with obstructive uropathy.

Materials and Methods:

This study involved 138 patients with obstructive uropathy with age ranged from 2 months to 73 years. Patients classified into two groups: Group (I): Includes 57 patients (41.3%), ureteric stents fixed to them; and Group (II): Includes 81 patients (58.6%) managed by other treatment modalities. All patients underwent clinical assessment, Laboratory and radiologic investigations: At presentation and postoperative. These included: Complete urine analysis, urine culture and sensitivity, serum creatinine, serum urea nitrogen, serum uric acid, serum sodium (Na), serum potassium (K), Fasting blood glucose level and blood picture and plain X-ray (KUB), abdominal ultrasonography (US), diuretic renography and retrograde pyelography.

Results:

Renal glomerular filtration rate (GFR) was used as an indicator for improvement of renal function after fixation of ureteric stent. In group I: 56 (71.8%) kidneys showed significant recovery compared to 61 kidneys (66.3%). In group II, there is statistically significant relation between renal perfusion and renal recovery (P < 0.004), statistically significant relation between parenchymal thickness and recovery in both groups (P < 0.0002), statistically significant relation between degree of corticomedullary differentiation and recovery (P < 0.0003) and statistically significant relationship between hemoglobin levels at presentation and the recoverability (P < 0.002).

Conclusion:

The predictors of renal recoverability revealed that ureteral stents alone can help in regaining renal function and significant improvement of clinical condition in patients with obstructive uropathy.

Mycobacterium tuberculosis pyomyositis in an infant

Mycobacterium tuberculosis is endemic to many parts of the world. It may have variable clinical presentations, especially in the pediatric age group. Presented here is the case of a 9-month old infant who was referred for infectious disease opinion when his thigh induration failed to improve after surgical drainage and a course of oral antibiotic therapy. Mycobacterial PCR on the operative sample fluid was found to be positive; and mycobacterial culture grew M. tuberculosis. He received 9 months of treatment with anti-TB medications, with excellent results and complete recovery. This is the first report of TB pyomyositis in an infant; and highlights the need to have a high index of suspicion for unusual organisms when conventional therapy fails to demonstrate expected results.

Clinical and cytogenetic study of a case with familial chromosomal translocation presenting with facial dysmorphism and axial neuropathy

We report on a 9-year-old female patient presenting with muscle weakness, facial dysmorphism and mild mental retardation. She had low birth weight, developmental delay, hypotonia and hyporeflexia and difficulties in climbing the stairs. EMG revealed axonal polyneuropathy affecting both upper and lower limbs. She was the child of non-consanguineous parents, her cytogenetic findings revealed 46,XX,t(12;14)(q14;q23). The mother's karyotype was normal 46,XX while the father's karyotype was 46,XY,t(12;14)(q14;q23) the same as his daughter. Her normal sister's karyotype was also 46,XX,t(12; 14) (q14;q23). Fluorescence in situ hybridization (FISH) was used to elucidate the breakpoints and Array-CGH was done for the patient to confirm the balanced translocation. This observation is of interest because it represents a rare case of a balanced translocation with abnormal phenotype. Mutant genes causing axonal neuropathy have been located on various chromosomes other than 12q14 or 14q24. This report shows the importance of molecular cytogenetics and its correlation with abnormal phenotype and the possibility of another gene locus at the presently studied chromosomal breakpoints. Detailed correlations between chromosome aberrations and their phenotypes are of invaluable help in localising genes for axonal polyneuropathy.

Balloon angioplasty optimization: should we measure balloon volume as well as pressure?

PURPOSE

To investigate the influence that measurement of balloon volume as a controlled variable in addition to balloon pressure has on the outcome of balloon angioplasty in an experimental model.

METHODS

One hundred and three segments of explanted normal porcine carotid arteries were obtained. Five were used as controls, and the remaining 98 were subjected to balloon angioplasty with simultaneous measurement of balloon volume and pressure. These arteries were randomized into two groups. In one group the endpoint of the angioplasty was determined by balloon pressure (pressure-limited group, PLG) and in the other group by balloon volume (volume-limited group, VLG). Pressure/volume curves for each procedure were constructed by continuous measurement of both parameters by a purpose-designed computer-controlled inflation device. The diameter of each arterial segment was measured by intravascular ultrasound (IVUS) and the ratio of the inflated balloon to arterial diameter calculated. Arterial appearances after angioplasty were recorded using IVUS.

RESULTS

The balloon volumes measured at the endpoint of angioplasty were significantly smaller in the PLG compared with the VLG (p < 0.001). Three types of pressure/volume curves were identified: A, B, and C. In the type A curves, IVUS identified fissures in 28% (17/60) and the examination was normal in 72% (43/60). In the type B curves, IVUS identified fissures in 44% (4/9), dissections in 22% (2/9), and the examination was normal in 33% (3/9). In the type C curves, IVUS identified fissures in 44% (4/9) and dissection in 56% (5/9) with no normal examinations. In undamaged arterial segments a very high correlation was achieved between balloon volume and the balloon/artery ratio (Pearson correlation = -0.979, R(2) = 0.957, p < 0.0001, n = 27).

CONCLUSION

The measurement of pressure and volume during angioplasty enabled the construction of pressure/volume curves that showed deviations from the curves obtained in air. The balloon volume results, and significant deviation of the curve shape from the control curve shape, predicted vessel damage, which was confirmed by the IVUS appearance of the vessel after angioplasty. When pressure was used as the endpoint of balloon inflation the balloons were significantly underdilated compared with the manufacturer's nominal sizes. These data indicate that monitoring of pressure and volume during angioplasty may provide an alternative method of predicting vessel damage.

Etiological factors of placenta previa at Rashed Ben Al-Hasen Hospital

Full text is available as a scanned copy of the original print version.

Thalassemia B with distal renal tubular acidosis: a previously undescribed association

An infant with beta thalassemia major and distal renal tubular acidosis is described. Screening of forty patients with beta thalassemia major revealed no evidence of renal tubular acidosis. Although the possibility of coincidence cannot be completely excluded, we suggest that beta thalassemia major should be added to the list of conditions associated with distal renal tubular acidosis.