Determination of Gestational Age: A Perspective With the Bangladeshi Ethnicity

Determination of gestational age (GA) with precision is vital to the proper care of pregnant mothers. Our present study aimed at determining the gestational ages by the ultrasonic measurements of four standard fetal parameters namely biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) specifically focusing on the Bangladeshi ethnic population. The current study is cross-sectional but data were collected in a prospective nature. There were 229 Bangladeshi women who had usual singleton fetuses with the evidence of menstrual dates by sonography before 14 weeks. Fetal anatomical structures have been scanned and measured at the time of sonographic inspection. Multiple linear regression models of GA by the date of last menstrual period (LMP) and GA by ultrasonographic measures have been fitted on four fetal parameters for our analysis. In the present analysis, we have found that all the response variables i.e. gestational age by LMP and gestational age by ultrasonography (USG) clearly depend on the fetal parameters. The best subsets regression analysis shows that BPD, AC, and FL are the best predictors of GA by LMP (adj R 2 = 96.54). In terms of Mallow’s Cp and adj R 2 , it is found that all the fetal parameters BPD, AC, HC and FL are important predictors for GA by USG. It has been observed that multiple fetal parameters measured by ultrasonography can be useful to predict gestational age during second and third trimesters. Precise estimation of gestational age by this method is helpful to reduce pregnancy-related complicacy and maternal death in the developing countries including Bangladesh

Kenaf cellulose-based poly(amidoxime) ligand for adsorption of rare earth ions

A well-known adsorbent, poly(amidoxime) ligand, was prepared from polyacrylonitrile (PAN) grafted kenaf cellulose, and subsequent characterization was performed by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and inductively coupled plasma mass spectrometry (ICP-MS). The adsorption capacities of the prepared ligand for rare earth metals are found to be excellent, with adsorptions of La 3+ , Ce 3+ , Pr 3+ , Gd 3+ and Nd 3+ experimentally determined to be 262, 255, 244, 241 and 233 mg·g −1 , respectively, at pH 6. The experimental values of the adsorption of rare earth metals are well matched with the pseudo-second-order rate equation. The reusability of the adsorbent is examined for seven cycles of sorption/desorption, demonstrating that the proposed adsorbent could be reused for over seven cycles without any significant loss in the original removal capability of the ligand

Bio-waste corn–cob cellulose supported poly (amidoxime) palladium nanoparticles for Suzuki-Miyaura cross-coupling reactions

Waste corn-cob cellulose supported poly(amidoxime) palladium nanoparticles (PdNs@PA) were prepared by the surface modification of waste corn-cob cellulose through graft co-polymerization and subsequent amidoximation. The supported nanoperticles showed high catalytic activity (45-400 mol ppm) towards Suzuki-Miyaura cross-coupling of aryl bromides/chlorides with organoboronic acids to give the corresponding biaryl products up to 99 % yield with high turnover number (TON) 19777 and turnover frequency (TOF) 4944 h−1. The PdNs@PA was easily recovered from the reaction mixture and reused several times without significant loss of its catalytic activity

Highly active kenaf bio-cellulose based poly (hydroxamic acid) copper catalyst for Aza-Michael addition and click reactions

Bio-heterogeneous kenaf cellulose supported poly(hydroxamic acid) Cu(II) complex and corresponding copper nanoparticles (CuN@PHA) were synthesized and characterized. Cellulose supported poly(hydroxamic acid) copper nanoparticles was successfully applied to the Aza-Michael addition reaction of amines with α,β-unsaturated carbonyl/cyano compounds and poly(hydroxamic acid) Cu(II) complex was applied to the Click reactions of organic azides with alkynes in presence of sodium ascorbate as highly active catalysts under mild reaction conditions. The copper nanoparticles (50 mol ppm) selectively boosted Aza-Michael addition reaction to give the corresponding alkylated products in up to 96 % yield, whereas poly(hydroxamic acid) Cu(II) complex (0.25 mol%) efficiently promoted Click reaction to give the corresponding 1,2,3-triazoles in up to 94 % yields. Excellent reusability of the supported copper catalysts were found with no significant loss of catalytic activity for several cycles having high turnover number (TON) 18000 and turnover frequency (TOF) 3000 h−1 in the Aza-Michael addition reaction

Synthesis of poly(hydroxamic acid) ligand from polymer grafted corn-cob cellulose for transition metals extraction

Poly(hydroxamic acid) ligand was synthesized using ester functionalities of cellulose-graft-poly(methyl acrylate) copolymer, and products are characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy analysis. The poly(hydroxamic acid) ligand was utilized for the sensing and removal of transition metal ions form aqueous solutions. The solution pH is found a key factor for the optical detection of metal ions, and the reflectance spectra of the [Cu-ligand]n+ complex were observed to be the highest absorbance 99.5% at pH?6. With the increase of Cu2+ ion concentration, the reflectance spectra were increased, and a broad peak at 705?nm indicated that the charge transfer (p-p transition) complex was formed. The adsorption capacity with copper was found to be superior, 320?mg?g-1, and adsorption capacities for other transition metal ions were also found to be good such as Fe3+, Mn2+, Co3+, Cr3+, Ni2+, and Zn2+ were 255, 260, 300, 280, 233, and 223?mg?g-1, respectively, at pH?6. The experimental data show that all metal ions fitted well with the pseudo-second-order rate equation. The sorption results of the transition metal ions onto ligand were well fitted with Langmuir isotherm model (R2?>?0.98), which implies the homogenous and monolayer character of poly(hydroxamic acid) ligand surface. Eleven cycles sorption/desorption process were applied to verify the reusability of this adsorbent. The investigation of sorption and extraction efficiency in each cycle indicated that this new type of adsorbent can be recycled in many cycles with no significant loss in its original detection and removal capability

Applications of bio-resource based sustainable heterogeneous Pd-Nanocatalyst for Cross-Coupling and Michael addition reactions

The development of efficient and cost-effective catalysts from renewable sources is crucial for sustainable chemistry. Herein, we developed a bio-heterogeneous Pd-nanocatalyst (PdNc@PA) by incorporating palladium nanoparticles into biodegradable kenaf-cellulose modified with poly(amidoxime) ligands. The catalyst has demonstrated remarkable stability and exceptional catalytic performance in a range of cross-coupling including Mizoroki-Heck, Suzuki-Miyaura, and Tamejiro-Hiyama reactions of inactivated aryl chlorides resulting in high yields of the desired coupling products. Additionally, PdNc@PA was also found to be effective in Michael addition reactions producing N, S, O-alkylated products in high yields. Furthermore, the PdNc@PA catalyst demonstrated robustness and recoverability allowing it to be reused across successive cycles without significant loss of catalytic activity. The incorporation of renewable resources in catalyst development offers an environmentally conscious alternative to traditional synthetic approaches. This research highlights the potential of utilizing biodegradable materials as catalyst supports, which could significantly diminish environmental impact and waste production. Moreover, this study demonstrates the versatility of PdNc@PA as a proficient and reusable catalyst for a diverse array of organic reactions. These discoveries provide an encouraging pathway towards the development of sustainable and economically viable catalysts suitable for industrial applications