SYNTHESIS AND CHARACTERIZATION OF AMINO-BASED CARBOXYMETHYL CHITOSAN AND ITS ADSORPTION FEATURES TOWARDS CU (II) AND ZN (II) IONS

This work was supported by the Program 211 of the Government of the Russian Federation, RFBR grants 17-03-00641 and 18-29-12129mk, the State Task from the Ministry of the Education and Science of the Russian Federation

Detection of Cancer Stem Cells in Colorectal Cancer: Histopathological and Immunohistochemical Study

BACKGROUND: Growing evidence supports the notion that the onset of tumorigenesis could occur through cancer stem cells (CSCs). These tumour cells show low proliferative rates, high self-renewal capacity, propensity to differentiate into active proliferating tumour cells & resistance to chemoradiotherapy thus, possibly causing local recurrences & metastasis formation. CD44 has been used as a marker to isolate CSCs from colorectal carcinoma (CRC).AIM: To investigate the immunohistochemical expression of cancer stem cells marker (CD44) in CRC and correlate its expression with the clinicopathological aspects, TNM staging and modified Dukes’ classification.MATERIALS AND METHODS: Tumour biopsies from colectomy specimens of 60 patients with CRC were stained with hematoxylin-eosin for histological evaluation then immunostained with monoclonal antibodies against CD44 which was detected in term of negative or positive expression.RESULTS: CD44 was demonstrated in 58.3% (35/60) of cases and showed statistically significant correlation with tumour site and histological type (p-value < 0.05). However, CD44 showed statistically insignificant inverse correlation with tumour invasiveness (T), lymph node status (N), grade, TNM stage grouping and modified Dukes’ classification, while it was directly correlated with distant metastasis (M) (p-value > 0.05). Chi-square /Fisher exact test proportion independence and the p-value are set significant at 0.05 level.CONCLUSION: the CD44 rate of expression is higher in the colon than rectum and in adenocarcinoma than mucinous and undifferentiated carcinoma. CD44 showed statistically insignificant relation with T, N, M, grade, TNM stage grouping and modified Dukes’ classification

Chitosan Functionalized with Carboxyl Groups as a Recyclable Biomaterial for the Adsorption of Cu (II) and Zn (II) Ions in Aqueous Media

The modification of chitosan represents a challenging task in obtaining biopolymeric materials with enhanced removal capacity for heavy metals. In the present work, the adsorption characteristics of chitosan modified with carboxyl groups (CTS-CAA) towards copper (II) and zinc (II) ions have been tested. The efficacy of the synthesis of CTS-CAA has been evaluated by studying various properties of the modified chitosan. Specifically, the functionalized chitosan has been characterized by using several techniques, including thermal analyses (differential scanning calorimetry and thermogravimetry), spectroscopies (FT-IR, XRD), elemental analysis, and scanning electron microscopy. The kinetics and the adsorption isotherms of CTS-CAA towards both Cu (II) and Zn (II) have been determined in the aqueous solvent under variable pH. The obtained results have been analyzed by using different adsorption models. In addition, the experiments have been conducted at variable temperatures to explore the thermodynamics of the adsorption process. The regeneration of CTS-CAA has been investigated by studying the desorption process using different eluents. This paper reports an efficient protocol to synthesize chitosan-based material perspective as regenerative adsorbents for heavy metals. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R13), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The work was supported by the Russian Foundation for Basic Research (RFBR) grant 18-29-12129mk. The researcher A.M. Abu El-Soad is funded by a scholarship under the Joint Executive program between the Arab Republic of Egypt and Russian Federation

Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

Forecasting the effects of smoking prevalence scenarios on years of life lost and life expectancy from 2022 to 2050: a systematic analysis for the Global Burden of Disease Study 2021

Background: Smoking is the leading behavioural risk factor for mortality globally, accounting for more than 175 million deaths and nearly 4·30 billion years of life lost (YLLs) from 1990 to 2021. The pace of decline in smoking prevalence has slowed in recent years for many countries, and although strategies have recently been proposed to achieve tobacco-free generations, none have been implemented to date. Assessing what could happen if current trends in smoking prevalence persist, and what could happen if additional smoking prevalence reductions occur, is important for communicating the effect of potential smoking policies. Methods: In this analysis, we use the Institute for Health Metrics and Evaluation's Future Health Scenarios platform to forecast the effects of three smoking prevalence scenarios on all-cause and cause-specific YLLs and life expectancy at birth until 2050. YLLs were computed for each scenario using the Global Burden of Disease Study 2021 reference life table and forecasts of cause-specific mortality under each scenario. The reference scenario forecasts what could occur if past smoking prevalence and other risk factor trends continue, the Tobacco Smoking Elimination as of 2023 (Elimination-2023) scenario quantifies the maximum potential future health benefits from assuming zero percent smoking prevalence from 2023 onwards, whereas the Tobacco Smoking Elimination by 2050 (Elimination-2050) scenario provides estimates for countries considering policies to steadily reduce smoking prevalence to 5%. Together, these scenarios underscore the magnitude of health benefits that could be reached by 2050 if countries take decisive action to eliminate smoking. The 95% uncertainty interval (UI) of estimates is based on the 2·5th and 97·5th percentile of draws that were carried through the multistage computational framework. Findings: Global age-standardised smoking prevalence was estimated to be 28·5% (95% UI 27·9–29·1) among males and 5·96% (5·76–6·21) among females in 2022. In the reference scenario, smoking prevalence declined by 25·9% (25·2–26·6) among males, and 30·0% (26·1–32·1) among females from 2022 to 2050. Under this scenario, we forecast a cumulative 29·3 billion (95% UI 26·8–32·4) overall YLLs among males and 22·2 billion (20·1–24·6) YLLs among females over this period. Life expectancy at birth under this scenario would increase from 73·6 years (95% UI 72·8–74·4) in 2022 to 78·3 years (75·9–80·3) in 2050. Under our Elimination-2023 scenario, we forecast 2·04 billion (95% UI 1·90–2·21) fewer cumulative YLLs by 2050 compared with the reference scenario, and life expectancy at birth would increase to 77·6 years (95% UI 75·1–79·6) among males and 81·0 years (78·5–83·1) among females. Under our Elimination-2050 scenario, we forecast 735 million (675–808) and 141 million (131–154) cumulative YLLs would be avoided among males and females, respectively. Life expectancy in 2050 would increase to 77·1 years (95% UI 74·6–79·0) among males and 80·8 years (78·3–82·9) among females. Interpretation: Existing tobacco policies must be maintained if smoking prevalence is to continue to decline as forecast by the reference scenario. In addition, substantial smoking-attributable burden can be avoided by accelerating the pace of smoking elimination. Implementation of new tobacco control policies are crucial in avoiding additional smoking-attributable burden in the coming decades and to ensure that the gains won over the past three decades are not lost

Synthesis and characterization of modified sulfonated chitosan for beryllium recovery

A new adsorbent, sulfated crosslinked chitosan (SGCH), has been synthesized for the effective extraction of beryllium ions from their aqueous solutions. In recent times, beryllium extraction has been of great importance because beryllium can be used in many applications such as in nuclear reactor, heat shields, high-technology ceramics, alloys and electronic heat sinks. SGCH has been synthesized by two successive phases. The first is the conversion of chitosan (CH) into non-soluble cross-linked chitosan (GCH) through the interaction between chitosan and glutaraldehyde. The second step is the formation of functional sulfonate groups onto the adsorbent material through the interaction of GCH with chlorosulfonic acid (sulfating agent). The role played by the sulfonate groups in the adsorption process was analyzed using FT-IR and SEM. Also, the role played by the solution pH, time, beryllium concentration and temperature on the batch adsorption process was investigated. Our results point to the successful preparation of SGCH adsorbent with high affinity for beryllium ions. The maximum sorption values of beryllium ions on the investigated biosorbent is 40.6 mg/g. The desorption of the loaded beryllium ions from the SGCH was achieved by using 1.5 M urea acidified by 0.6 M H2SO4

Eco-friendly self-terminated process for preparation of CaO catalyst based on chitosan production wastes for biodiesel production

One of the major obstacles to the realization of a sustainable planet is the handling of liquid waste, which is where Chitosan production waste (CPW) have been becoming a significant environmental issue. Chitosan production waste derived CaO catalyst (CPW-CaO) was synthesized through a self-termination precipitation of acidic waste (de-mineralization step) with alkali waste (de-proteination/de-acetylation) then calcination and utilized as an eco-friendly and cost-effective catalyst to generate biodiesel from Soybean deodorizer distillate oil (SDDO). XRD, EDS, FTIR, SEM, and BET were used to characterize CPW-CaO. The catalyst demonstrated exceptional catalytic performance in the conversion of SDDO to sustainable biodiesel which matched the EN fuel specifications at 8% catalyst dosage, 12:1 ration of methanol to SDDO, 2 h, and 65 °C reaction temperature as optimum conditions that yielding a 97.1% conversion. For the first four reaction cycles, the CPW-CaO catalyst was able to produce a comparatively high conversion of biodiesel, according to the reusability study. The catalyst regeneration can be recycled for more than four cycles to produce a comparatively high biodiesel yield. The results of this study provide a cost-effective and ecologically friendly method for producing biodiesel

Appreciatively Efficient Sorption Achievement to U(VI) from the El Sela Area by ZrO₂/Chitosan

The need to get uranium out of leaching liquid is pushing scientists to come up with new sorbents. This study uses the wet technique to improve the U(VI) sorption properties of ZrO2/chitosan composite sorbent. To validate the synthesis of ZrO2/CS composite with Zirconyl-OH, -NH, and -NH2 for U(VI) binding, XRD, FTIR, SEM, EDX, and BET are used to describe the ZrO2/chitosan wholly formed. To get El Sela leaching liquid, it used 150 g/L H2SO4, 1:4 S:L ratio, 200 rpm agitation speed, four hours of leaching period, and particle size 149–100 µm. In a batch study, the sorption parameters are evaluated at pH 3.5, 50 min of sorbing time, 50 mL of leaching liquid (200 mg/L U(VI)), and 25 °C. The sorption capability is 175 mg/g. Reusing ZrO2/CS for seven cycles with a slight drop in performance is highly efficient, with U(VI) desorption using 0.8 M acid and 75 min of desorption time. The selective U(VI) recovery from El Sela leachate was made possible using ZrO2/CS. Sodium diuranate was precipitated and yielded a yellow cake with a purity level of 94.88%

Decontamination of Uranium-Polluted Groundwater by Chemically-Enhanced, Sawdust-Activated Carbon

The preparation of highly efficient and low-cost activated carbon from sawdust was achieved for the treatment of uranium-contaminated groundwater. The adsorption properties of the synthesized activated carbon, as well as their ability to be reused, were assessed. The obtained results demonstrated that sawdust activated carbon (SDAC) and its amine form (SDACA) had high affinity towards uranium ions at pH values of 4.5 and 5 for SDAC and SDACA, respectively. The experimental results showed that the maximum adsorption capacity of uranium was 57.34 and 76.7 mg/g for SDAC and SDACA, respectively. A maximum removal efficiency of 89.72% by SDAC and 99.55% by SDACA were obtained at a solid/liquid ratio of 8 mg/mL. The removal mechanism of uranium by SDAC and SDACA was suggested due to interaction with the amine and carboxylic groups. The validation of the method was verified through uranium separation from synthetic as well as from groundwater collected from water wells in the Wadi Naseib area, Southwestern Sinai, Egypt