Unusual CO2 Adsorption in ZIF-7: Insight from Raman Spectroscopy and Computational Studies

Here, we use Raman spectroscopy to investigate temperature-dependent changes in the atomic-scale structure of the zeolitic imidazolate framework ZIF-7 in a CO₂ atmosphere and uncover the mechanism of maximal CO₂ adsorption at 206 K. At 301 K, the Raman spectra of ZIF-7 at various CO₂ gas pressures reveal a narrow-pore (np) to large-pore (lp) phase transition commencing at 0.1 bar as a result of adsorption of CO₂, as evident in the appearance of Fermi resonance bands of CO₂ at 1272 and 1376 cm^-1. Moreover, the Raman inactive bending mode of CO₂ becomes active due to geometrical distortion of adsorbed CO₂. It further splits into two peaks due to hydrogen bonding interactions between CO₂ and the benzene ring of the benzimidazole linker ZIF-7, as supported by our computational studies. In addition, the interaction between CO₂ molecules plays a key role. Upon reducing the temperature at 1 bar CO₂ gas pressure, ZIF-7 exhibits softening of the imidazole puckering mode and the Fermi resonance CO₂ band due to interactions between CO₂ and the framework through hydrogen bonding. At 206 K, substantial modification in the lattice mode and disappearance of the Raman inactive CO₂ bending mode confirm the changes in the size of the pore cavity through structural rearrangements of CO₂.

Epidemiology and outcome of 2,590 burned patients in Northwest Iran

Burns are calamities with considerable morbidity and mortality rates. We attempted to examine the epidemiology of burns in Zanjan city, in northwest Iran, by a systematic study of existing information. The medical files of 2,590 thermal burn patients treated in our hospital in Zanjan city, Iran, from December 2010 to November 2016 were studied. Patient information, including age, sex, burn degree, season, cause of burn, hospital stay and treatment results were analyzed. About 65% of the patients were male (n=1691). Most burns (92.8%) were less than 30% total body surface area. Mean age and hospital stay were 25.4 years old and 9.1 days, respectively. The most common causes of burn were hot liquids, gas explosion and fire, respectively. Except for self-immolation, which was more common among men, there was no significant relationship between cause of burn and the studied variables. The six-year mortality rate was 2.9%, and was more common in the years 2011 to 2013. In addition, distribution of causes of burn had a significant trend (variation). Fire burn had a decreasing trend and gas and chemical burn had increasing trends in this period. In northwest Iran the causes of burn changed over the six years. Chemical burns, gas explosion burns and burn mortality increased. Some of these results were due to economic and pharmaceutical sanctions in Iran. Because of Iran's industrial development, it is recommended that preventive measures for chemical, gas and electrical burns be conducted.

The role of miR-146a on NF-κB expression level in human umbilical vein endothelial cells under hyperglycemic condition

Emerging studies have been shown that the expression of micrRNA-146a (miR-146a, as a regulator of nuclear factor κB (NF-κB)), is changed in diabetic patients and animals. This study was designed to evaluate the possible role of miR-146a in the pathogenesis of diabetes-related microvascular complications. Concurrent with the creation of cellular hyperglycemia (25 mmol/L for 24 h), human umbilical vein endothelial cells (HUVECs) were transfected with 20 nmol/L of hsa-miR-146a antagomir or scramble using HiPerFect reagent (Qiagen). D-mannitol was used as osmotic control. Hyperglycemia increased the NF-κB gene expression and protein activity (as an inflammation index) in cultured HUVECs. Moreover, the gene expression level of miR-146a, and its target proteins, tumor necrosis factor receptor-associated factor 6 (TRAF6) and interleukin-1 receptor-associated kinase 1 (IRAK1) were increased under hyperglycemic condition. The knockdown of miR-146a by transfection of miR-146a antagomir notably increased the NF-κB activity and decreased the NF-κB mRNA in hyperglycemic HUVECs. Furthermore, miR-146a antagomir significantly increased IRAK1 and TRAF6 mRNA levels under hyperglycemic condition. These results demonstrate that the expression of miR-146a is upregulated in HUVECs during early phase of hyperglycemic condition possibly to regulate the NF-κB activity through inhibition of IRAK1 and TRAF6 (Fig. 4, Ref. 32).

Temperature and Pressure Dependent Phase Transitions of β'-LiZr2(PO4)3 Studied by Raman Spectroscopy

LiZr2(PO4)3 (LZP) belongs to the NASICON family of compounds whose ionic conductivity can be tuned by substitution of different cations or by increasing the temperature or pressure. Besides its conductivity, thermal and electrochemical stability makes it useful as a cathode material for lithium-ion energy storage devices. Temperature dependent Raman spectroscopic studies were carried out on the monoclinic (β') phase of LZP in the temperature range 298-853 K. A reversible structural phase transition driven by disorder in lithium sites is observed at 603 K. The spectral data enable an understanding of dynamics of the mobile Li ion and PO4 internal modes across the orthorhombic structural phase transition. On the basis of these studies, a reported change in the conductivity around 600 K is explained. High pressure Raman spectroscopic measurements on β'-LiZr2(PO4)3 reveal the onset of a structural phase transformation at 3.8 GPa and amorphization above 10 GPa. On decompression from 26 GPa, the amorphous phase remains unchanged, indicating irreversible nature of pressure-induced amorphization. Three low frequency Raman modes at 100, 124, and 144 cm(-1), which soften with an increase in pressure could be the driving force for the phase transition at 3.8 GPa. Pressure-induced phase transition prior to amorphization in β'-LiZr2(PO4)3 could be due to collapse of Zr-O-P bond angles. Pressure-induced amorphization in this compound might be due to kinetic hindrance of equilibrium decomposition.

Comparative Raman spectroscopic study of phase stability and anharmonic effects in AZr2(PO4)3 (A=K, Rb and Cs)

AZr2(PO4)3 (A=Na, K, Rb, Cs) are a set of framework structured compounds that exhibit tunable ultralow thermal expansion over the wide temperature range of 293-1273K. We report a systematic Raman spectroscopic investigation on AZr2(PO4)3 (A=K, Rb and Cs) compounds as a function of temperature in the range 80-860K and pressures of up to 32GPa. To get insight into the thermal expansion property, phonon anharmonicity has been investigated by studying the temperature and pressure dependence of Raman peak shifts and line widths and computed bulk modulus. We have compared the phase transition and amorphization pressures of the various members of AZr2(PO4)3 to account for the stability of the ambient rhombohedral phase. We find that unlike most of the anomalous thermal expansion materials, in AZr2(PO4)3 (A=K, Rb and Cs), the phonons that are anharmonic with temperature do not necessarily exhibit anharmonicity with pressure.

Counseling and Harm Reduction Centers for Vulnerable Women to HIV/AIDS in Iran

BACKGROUND

Human immunodeficiency virus (HIV) is a public health challenge facing both developing and developed nations. Although injecting drug use is even the main route of HIV transmission in Iran, sexual route is rising gradually. Vulnerable women have been considered as important bridging population for driving HIV epidemics. To increase the access to vulnerable women, in 2007, 5 pilot centers were established in risky areas to deliver comprehensive services to women who themselves or their spouses are engaged in drug use, risky sexual behavior or have history of imprisonment. Management of Sexually Transmitted Infection, psychological counseling and harm reduction are provided by female staff. The aim of this study was to report the activities conducting in 2008.

METHODS

Registered information was used to assess the demographic characteristic, HIV/ AIDS related risk factors and services delivered to clients.

RESULTS

Till March 2008, 442 clients have been admitted. Most of them (36.2%) had 25-34 years old. 14.3% were illiterate and 31% were totally jobless. The most prevalent risk factors were risky sexual behavior (27.1%) and non-injecting drug use (23.2%). Injecting drug use was detected in 11.3% of attendees. Dividing clients according to marital status, risky sexual behavior was the main risk factor in unmarried (40.2%) and divorced (26.9%) but in married and widow ones, non-injecting drug use was the most (25.8% and 36.5% respectively). Harm reduction (40.5%) and counseling (36.6%) were the most delivered services.

CONCLUSION

Since vulnerable women play a critical role to spread HIV-epidemic to general population, increasing centers provide more access to this population.

Introducing a quantitative method to calculate the rate of primary infertility

BACKGROUND

In the previous studies, the rate of primary infertility was reported differently. It seems the main reasons are related to the different methods of data collection and information analysis. Therefore, introducing a precise method to determine the infertile couples and the population exposed to the risk of infertility is an important issue to study primary infertility.

METHODS

The proposed methodology for assessing primary infertility rate has been designed and applied by Avicenna Research Institute in a national survey. Sampling was conducted based on probability proportional to size cluster method. In this survey, after reviewing the former studies, the reproductive history was used as a basis for data collection. Every reproductive event was recorded with a code and a date in the questionnaire. To introduce a precise method, all possible events were considered thoroughly and for each situation, it was determined whether these cases should be considered in numerator, denominator or it should be eliminated from the study. Also in some situations where the correct diagnosis of infertility was not possible, a sensitivity analysis was recommended to see the variability of results under different scenarios.

CONCLUSION

The proposed methodology can precisely define the infertile women and the population exposed to the risk of infertility. So, this method is more accurate than other available data collection strategies. To avoid bias and make a consistent methodology, using this method is recommended in future prevalence studies.

Evaluation of semen quality in patients with malignancies referred for sperm banking before cancer treatment

Different cancer treatments such as chemotherapy and radiotherapy can lead to azoospermia and even sterility for an unknown period. Whether the type of cancer could affect semen quality or not is under debate. In this study, we have reviewed semen parameters of men with cancer who deposited their sperm samples at the Avicenna Research Institute tissue bank before undergoing cytotoxic treatment. This descriptive retrospective study examined 73 cases referred to sperm bank, because of malignancy, prior to initiation of cancer treatments including chemotherapy and radiotherapy. The data recorded were age, marital status, reproductive history, semen analysis reports and cancer history of the patients. Semen samples were analysed according to recommendations of the World Health Organization (1999) before freezing. Results of the analysis showed that 71.2% (52) of patients had oligozoospermia, 93.2% (68) teratozoospermia and 86.3% (63) asthenozoospermia. Different groups of cancer patients did not show any differences in oligozoospermia, teratozoospermia and asthenozoospermia. Impaired spermatogenesis even prior to cancer treatment indicates the importance of fertility preservation. As the majority of patients had suitable specimens for freezing and assisted reproduction, sperm banking is recommended to be performed promptly and before any treatment, especially surgery.

The Association between Sporadic Alzheimer's Disease and the Human ABCA1 and APOE Gene Polymorphisms in Iranian Population

BACKGROUND

Apolipoprotein E (APOE), which its ε4 allele has been reported as a risk factor in late onset Alzheimer's disease (AD), is the main cholesterol carrier in the brain. ATP-binding cassette transporter A1 (ABCA1) gene on chromosome 9, which has been known by genome-wide AD linkage study, has an important role in cellular cholesterol efflux. This study determines the association between sporadic AD and the human ABCA1 and APOE gene polymorphisms in Iranian population.

METHODS

154 AD cases and 162 control subjects from Iranian population were genotyped for APOE genotypes and ABCA1 polymorphism (R219K).

RESULTS

The frequency of ε2ε3 genotype was higher in control subjects comparing AD patients but was not significant (13% versus 5.8%) and ε3ε4 genotype frequency was significantly higher in AD cases comparing with control subjects. APOE-ε2 allele frequency in cases was lower than control subjects but this difference was not significant (4.5% versus 8%). Individuals carrying ε4 allele, developed AD 6.5 times more than non-carriers (OR=6.52, 95%CI=2.63-16.17). There was no significant association between ABCA1 polymorphism and AD.

CONCLUSION

Unlike other studies, R219K polymorphism was not dependent on gender and APOE-ε4 allele and there was no association between APOE and ABCA1 in AD patients compared to controls.

Association between Alzheimer's Disease and Apolipoprotein E Polymorphisms

BACKGROUND

Alzheimer's disease as a neurodegenerative disorder is the commonest type of dementia. A growing number of genes have been reported as the risk factors, which increase the susceptibility to Alzheimer's disease. Apolipoprotein E (APOE), which its ε4 allele has been reported as a risk factor in late onset Alzheimer's disease (AD), is the main cholesterol carrier in the brain. The main goal of this study was to assess the role of APOE genotypes and alleles in AD in Iranian population.

METHODS

This study was performed in Tehran, Iran from 2007 to 2008. Totally, 154 AD cases and 162 control subjects from Iranian population were genotyped for APOE using PCR method. Genotype and alleles frequencies for APOE were calculated and compared between AD case and control subjects by χ2 or Fisher's exact test. Type one error assumed less than 0.05.

RESULTS

The frequency of ε2ε3 genotype was significantly higher in control subjects than AD patients was (13.5% versus 5.2%, P< 0.05) and ε3ε4 genotype frequency was significantly higher in AD cases compared with control subjects. APOE -ε2 allele frequency in cases was lower than that of control subjects but this difference was not significant (4.2% versus 7.7%).

CONCLUSION

It seems that individuals carrying ε4 allele, develop AD 6.5 times more than non-carriers do (OR= 6.566, 95% CI= 2.89-14.92). It has been reported that ε4 allele acts in dose- age-dependent manner but we have shown that the risk of developing AD in male APOE -ε4 allele carriers is higher than that of female ε4 carriers.

Novel extreme homozygote haplotypes at the human caveolin 1 gene upstream purine complex in sporadic Alzheimer's disease

Aberrant expression of the caveolin-1 (CAV1) gene is associated with Alzheimer's disease (AD) brain. We have recently reported a polymorphic purine stretch located at between 1.8 and 1.5 kb flanking the CAV1 gene, whose alleles and genotypes are associated with late-onset AD. Extra-short homozygote haplotypes were observed that were present only in the AD cases. Following an independent case/control study, we report alleles at the other extreme of the allele range, haplotypes of which were observed to be homozygous across the region in the AD cases. We propose that there is a window for the length of motifs and haplotypes in the controls. Homozygosity for shorter and longer motifs and haplotypes was linked with AD in our study. Our findings elucidate novel predisposing haplotypes at the CAV1 gene purine complex, and confirm the role of this region in the etiopathophysiology of late-onset AD.

A novel polymorphic purine complex at the 1.5 kb upstream region of the human caveolin-1 gene and risk of Alzheimer's disease; extra-short alleles and accumulated allele homozygosity

Crucial interaction of caveolin-1 (CAV1) with beta- and gamma-secretases, and aberrant expression of the gene encoding this protein in Alzheimer's disease (AD) support a role for CAV1 in the pathophysiology of this disease. We report a novel polymorphic purine complex stretching approximately 150 bp of genomic DNA at the 1.5 kb upstream region of the human CAV1 gene, alleles and genotypes of which are associated with sporadic late-onset AD. Extra-short alleles were observed in the case group that were absent in the control subjects. Remarkably, 63% of these alleles were observed to be homozygous in length, forming 23.7% of the homozygote length compartment in the AD cases (chi(2) = 19.08, df = 1, P < 0.000007). Increased homozygosity for length was also observed at this region in the Alzheimer's cases, for the allele lengths shared by the case and control groups [(chi(2) = 30.75, df = 1, P < 0.0000000, OR = 4.54, CI 95% (2.56-8.3)]. This region contains GGAA and GAAA motifs, the consensus binding sites for the Ets and IRF family transcription factors, respectively, and is highly conserved in distantly related non-human primates in respect with location and motif sequence. The effect of this complex sequence on the expression of CAV1, and the related mechanisms in the pathophysiology of AD remain to be clarified.

Life table and temperature-dependent development of Diadegma anurum (Hymenoptera: Ichneumonidae) on its host Plutella xylostella (Lepidoptera: Plutellidae)

Life table and temperature-dependent development of Diadegma anurum (Thomson) (Hymenoptera: Ichneumonidae) was studied on diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae) reared on cabbage, Brassica oleracea L. variety capitata, and cauliflower, Brassica oleracea L. variety botrytis. The developmental periods of immature stages were recorded at five constant temperatures (15, 20, 25, 30, and 35 degrees C). The population of D. anurum and its host failed to survive at 35 degrees C. Mean total development time of D. anurum was not significantly different on two host plants except at 25 degrees C. The developmental zero (low temperature threshold) was estimated to be 7.0 and 6.9 degrees C, and the thermal constant was 282.3 and 277.7 DD on cabbage and cauliflower, respectively, using the linear model. Data were fitted to four nonlinear temperature-dependent models. Evaluation of the models was carried out based on the following criteria: fit to data, number and biological values of the fitted coefficients, and accuracy on the estimation of the thresholds. Consequently, the Briere-1 model was accepted and recommended for the description of temperature-dependent development of D. anurum. The life table parameters of D. anurum were also studied at 25 degrees C constant temperature. Its intrinsic rate of increase (rm) and mean generation time (T) were estimated to be 0.169 and 16.083 d on cabbage, respectively. The life table parameters of D. anurum can be used to develop the models of population dynamics and prediction.

Effects of renal transplantation on serum-free and total PSA levels

PURPOSE

This study was undertaken to evaluate the effects of renal transplantation on serum level of free and total PSA.

MATERIALS AND METHODS

In this study, we included 30 male patients with a mean age of 46 years with end-stage renal disease undergoing renal transplantation at our department. None of the patients had any history of prostate cancer. All patients had immediate onset of renal function after transplantation, defined by a spontaneous decrease in serum creatinine on postoperative day 1 and a subsequent decrease daily during week 1. Renal transplantation included living-related donors in all patients. Blood samples were obtained before and at posttransplant day 6 before removal of Foley catheter. Measurements of free PSA and total PSA were performed with immunofluorometric assays. Glomerular filtration rates were monitored by analyzing serum creatinine. The significance of changes with time was estimated by the Wilcoxon signed ranks test for paired observations with P<.05 considered statistically significant.

RESULTS

The mean free and total PSA levels before transplantation were 0.22 (range, 0.0.05 to 0.4) and 1.5 ng/mL (range, 0.1 to 2.9), respectively. There was a significant decrease (30% of original levels) in serum fPSA at posttransplant day 6 (P<.05) in all patients. There was no significant changes of total PSA at posttransplant day 6.

CONCLUSIONS

These results verify the hypothesis that free PSA is eliminated from the blood circulation by glomerular filtration and severe renal failure influences its levels. Thus, we should consider different cutoffs for free to total ratio before and after renal transplantation.

Methanol poisoning: acute MR and CT findings in nine patients

INTRODUCTION

Methanol poisoning is an uncommon but potent central nervous system toxin. We describe here the CT and MR findings in nine patients following an outbreak of methanol poisoning.

METHODS

Five patients with a typical clinical presentation and elevated anion and osmolar gaps underwent conventional brain MRI with a 1.5-T Gyroscan Interna scanner. In addition nonenhanced CT was performed in another three patients with more severe toxicity.

RESULTS

Bilateral hemorrhagic or nonhemorrhagic necrosis of the putamina, diffuse white matter necrosis, and subarachnoid hemorrhage were among the radiological findings. Various patterns of enhancement of basal ganglial lesions were found including no enhancement, strong enhancement and rim enhancement.

CONCLUSION

A good knowledge of the radiological findings in methanol poisoning seems to be necessary for radiologists. The present study is unique in that it enables us to include in a single report most of the radiological findings that have been reported previously.

Lateral neck radiography for prediction of difficult orotracheal intubation

BACKGROUND AND OBJECTIVES

Failed endotracheal intubation is a principal cause of morbidity and mortality in anesthetized patients. The aim of this study was to investigate the efficiency of lateral neck radiography in predicting difficult intubation.

METHODS

In a prospective triple-blind study, 100 patients (aged 18-89 yr), scheduled for elective surgery were randomly selected. Lateral neck X-ray was obtained from each of the patients before operation. Several angles and parameters on the X-ray were proposed to illustrate a relationship with easy or difficult intubation. A radiologist recorded these angles before the operation. An anaesthesiologist also determined the Mallampati score preoperation. At the time of intubation, two other anesthesiologists performed a laryngoscopy and, according to established criteria, identified the patients as easy or difficult intubation. The results were then compared with each other.

RESULTS

Fifteen patients were identified as having difficult intubation (laryngoscopy Grades III and IV). Sensitivity and specificity of the Mallampati Class test were 26% and 100%, respectively. The sensitivity and specificity of the lateral neck X-ray for three measured angles were 100%. The positive and negative predictive values (NPVs) for those angles were 100% and for Mallampati classification were 100% and 80%, respectively.

CONCLUSIONS

Compared to the Mallampati Class test, our method of analyzing the lateral X-ray, although not as easy and universally applicable as Mallampati Class test, proved to be a suitable method for predicting difficult intubation.

Effects of tetrahydroaminoacridine (THA) on functional recovery after sequential lesion of the entorhinal cortex

Unilateral lesions of rat entorhinal cortex produce a transitory performance deficit on spatial learning tasks, such as reinforced alternation in a T-maze. Tetrahydroaminoacridine (THA), a cholinesterase inhibitor, was administered to determine its effects on behavioral recovery using a reinforced alternation task in a T-maze. Rate of recovery after unilateral entorhinal lesion was not affected by a low dose of THA (0.05 mg/kg), while a higher dose (5.0 mg/kg) impaired recovery. Behavioral recovery was subsequently evaluated in the same rats following lesions to the contralateral entorhinal cortex. Serial bilateral lesions of the entorhinal cortex are known to produce a prolonged performance deficit on the alternation task. The 0.05 mg/kg THA group exhibited an intermediate rate of recovery, between the undamaged control group and bilateral lesion-saline injected groups. The group receiving 5.0 mg/kg of THA after bilateral lesion did not differ from the bilateral lesion-saline group. The failure of THA to significantly improve functional recovery in rats with lesions of the entorhinal cortex indicates that the compound may have limited applicability in treating human neurodegenerative disorders such as Alzheimer's disease.

Polydrug use by high-school students: involvement and correlates

A hierarchical cluster analysis was performed on 273 self-admitted high-school drug users' descriptions of how frequently they had employed marijuana, stimulants, depressants, hallucinogens, solvents, and opiates during the preceding year. Four types of polydrug users were identified and considered as representing an ordinal scaling of the students along a continuum of overall involvement with drugs, and each user was assigned an index score based on his typal membership. A stepwise multiple regression was then performed to discover which of the students' background characteristics and attitudes were related to their polydrug involvement scores. The search for pleasant sensations, the desire for expanded creativity, and the belief that one would cease taking drugs if they were conclusively shown to be harmful were more powerful predictors of polydrug involvement than any of the sociocultural factors.