Women's reproductive span: a systematic scoping review.

STUDY QUESTION: What is the scope of literature regarding women's reproductive span in terms of definitions, trends and determinants? SUMMARY ANSWER: The scoping review found a wide variation in definitions, trends and determinants of biological, social and effective women's reproductive span. WHAT IS KNOWN ALREADY: A woman's reproductive span refers to her childbearing years. Its span influences a woman's reproductive decisions. STUDY DESIGN SIZE DURATION: A systematic scoping review was conducted. We searched MEDLINE, PubMed, JSTOR, CINAHL, Web of Science and Scopus electronic databases from inception to January 2021 without imposing language or date restrictions. We searched unpublished sources including the Global Burden of Disease, Demographic and Health Surveys, and National Health and Nutrition Examination Surveys. The list of relevant references was searched by hand. Sixty-seven reports on women's reproductive span were included in this review. PARTICIPANTS/MATERIALS SETTING METHODS: This scoping systematic review followed an established framework. The reporting of this scoping review followed the reporting requirements provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Extension for Scoping Reviews. Identified records were independently screened and data were extracted. We performed conceptual synthesis by grouping the studies by available concepts of reproductive span and then summarized definitions, measures used, temporal trends, determinants, and broad findings of implications on population demographics and assisted reproduction. Structured tabulation and graphical synthesis were used to show patterns in the data and convey detailed information efficiently, along with a narrative commentary. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 67 relevant reports on women's reproductive span were published between 1980 and 2020 from 74 countries. Most reports (42/67) were cross-sectional in design. Literature on reproductive span was conceptually grouped as biological (the interval between age at menarche and age at menopause), effective (when a woman is both fertile and engaging in sexual activity) and social (period of exposure to sexual activity). We summarized the working definitions, trends and determinants of each concept. Few articles addressed implications on demographics and assisted reproduction. LIMITATIONS REASONS FOR CAUTION: A formal assessment of methodological quality of the included studies was not performed because the aim of this review was to provide an overview of the existing evidence base regardless of quality. WIDER IMPLICATIONS OF THE FINDINGS: The review produced a comprehensive set of possible definitions of women's reproductive span, trends, and potential determinants. Further advancement of these findings will involve collaboration with relevant stakeholders to rate the importance of each definition in relation to demography and fertility care, outline a set of core definitions, identify implications for policy, practice or research and define future research opportunities to explore linkages between reproductive spans, their determinants, and the need for assisted reproduction. STUDY FUNDING/COMPETING INTERESTS: This work received funding from the UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), a cosponsored programme executed by the World Health Organization (WHO). The authors had no competing interests. STUDY REGISTRATION NUMBER: N/A.

Coupled adsorption-photocatalytic degradation of crystal violet under sunlight using chemically synthesized grafted sodium alginate/ZnO/graphene oxide composite.

This research aimed to synthesize natural polymer nanocomposite and employ it for coupled adsorption- photocatalytic degradation of crystal violet. Sodium alginate-g-poly (acrylic acid-co-cinnamic acid) and its composites with ZnO nanorods and graphene oxide sheets were synthesized and characterized using FT-IR, XRD, SEM, HR-TEM and DR/UV-vis spectroscopy. The adsorption efficiency of samples for crystal violet has been studied in the dark. The effect of different parameters as pH, initial dye concentration, contact time and temperature on the adsorption efficiency of the synthesized sample has been examined. Kinetics studies showed that the adsorption of all samples was well described by the pseudo-second-order model and the equilibrium adsorption results fitted Freundlich model. The maximum adsorption capacity achieved at pH 5.0 was 13.85 mg g-1. Thermodynamic studies exhibited that the adsorption is spontaneous, endothermic in nature and leads to higher entropy. Coupled adsorption-photocatalytic degradation studies under sunlight showed an enhancement in the removal efficiency by 10%. In the case of sodium alginate-g-poly (acrylic acid-co-cinnamic acid)/ZnO/graphene oxide composite, the removal efficiency after 5 h under sunlight was 94% versus 84% in the dark.

Synthesis and characterization of methyl pyrazolone functionalized magnetic chitosan composite for visible light photocatalytic degradation of methylene blue.

TiO2/Fe3O4, TiO2/Fe3O4/chitosan and Methylpyrazolone functionalized TiO2/Fe3O4/chitosan (MPyTMChi) were successfully prepared. The chemical structure of the prepared materials was confirmed by FT-IR spectra, XRD, SEM and TEM. BET surface area increased from 2.4 to 3.1m2/g, Eg decreased from 2.58 to 2.25eV and more quenching of PL emission spectra was observed upon functionalization of TMChi by MPy. Moreover, high Ti and oxygen percentages were detected by EDX. Magnetization value (Ms) reached 21 emu.g-1 for MPyTMChi. MPyTMChi showed enhanced photocatalytic degradation rate of methylene blue (MB) dye under visibe light irradiation (99.8% after 40min) as compared with that for TiO2/Fe3O4 (96.7% after 100min) and TMChi (98.9% after 60min), respectively. It was regarded that the photocatalytic degradation of MB dye on MPyTMChi follows apparent pseudo-first-order according to the Langmuir-Hinshelwood (L-H) model and kapp value was 0.089min-1. Active species trapping experiment revealed that h+ and O2- played the main role in the photodegradation of MB dye while OH quenching did not greatly affect photodegradation rate. Additionally, MPyTMChi can be efficiently reused for six repetitive cycles. MPyTMChi showed higher antimicrobial activity against gram-positive, gram- negative bacterial and fungal strains while large inhibition zone was observed for gram-positive bacteria.

Preparation and characterization of polymer coated partially esterified sugarcane bagasse for separation of oil from seawater.

Sugarcane bagasse (B), a low-cost agricultural waste, was modified via esterification and coating with polyacrylonitrile (PAN) and evaluated as a hydrophobic sorbent for diesel oil removal from artificial seawater. Esterification was carried out using stearic acid (SA) and CaO, the reaction conditions, including B:SA mass ratio, CaO concentration, reaction time and temperature were optimized. Additional hydrophobicity was achieved by coating the esterified bagasse (EB) with a hydrophobic polymer (PAN). The advantages of hydrophobicity were clearly expressed by decreased water absorption capacity and increased oil adsorption capacity. The presence of hydrophobic groups was evidenced through Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. FTIR spectroscopy showed some changes in the spectrum of B. XRD patterns indicated that the crystalline structure of B turned amorphous. SEM micrographs illustrated that the surface of EB roughened and PAN was unevenly deposited on it, which led to an increase in the surface area of both sorbents. Moreover, efficient desorption and resorption of diesel oil, paraffin oil, gasoline oil and vegetable oil were recorded in six cycles. Generally, the results are promising and the prepared sorbents can positively contribute to environmental remediation.

Synthesis, characterization and antimicrobial properties of grafted sugarcane bagasse/silver nanocomposites.

Sugarcane bagasse (SCB) was grafted with acrylamide (AAm) and glycidyl methacrylate (GMA) by chemical oxidation method. The effect of monomer/initiator molar ratio, reaction time, reaction temperature and material to liquor ratio on the degree of grafting was investigated. The optimum conditions for grafting were: monomer/initiator molar ratio 1 for AAm and 2 for GMA, reaction time 4h, reaction temperature 80°C and materials to liquor ratio 1:20. Silver nanoparticles (AgNPs) were prepared and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ungrafted SCB, SCB-g-AAm and SCB-g-GMA were impregnated into silver (Ag) nanoparticles colloidal solution. The ungrafted SCB, grafted SCB and their nanocomposites with Ag nanoparticles were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The grafted SCB/Ag nanoparticles exhibit better antimicrobial activity against Escherichia coli as the model Gram-negative bacteria, Staphylococcus aureus as the model Gram-positive bacteria and Aspergillus flavus and Candida albicans (yeasts) than ungrafted SCB/AgNPs.