Removal of perfluoroalkyl acids (PFAAs) from aqueous solution by water hyacinth (Eichhornia crassipes): Uptake, accumulation, and translocation.

Although Eichhornia crassipes, commonly known as water hyacinth, has been widely used in wastewater treatment, further investigations are still needed to explore the removal efficiency of perfluoroalkyl acids (PFAAs) from the aqueous environment using this floating aquatic plant. In this study, a hydroponic experiment was conducted to assess accumulation, bioconcentration factors (BCFs), translocation factors (TFs), and removal rates of eight PFAAs by water hyacinth. The obtained results indicated that all PFAAs, including five perfluoroalkyl carboxylic acids (PFCAs) with chain lengths C4-C8 and three perfluoroalkyl sulfonic acids (PFSAs) with C4, C6, and C8, were readily accumulated in water hyacinth. Throughout the duration of the experiment, there was a noticeable increase in PFAA concentrations and BCF values for different plant parts. For the root, PFAAs with more carbon numbers showed a higher uptake than the shorter homologues, with PFSAs being more readily accumulated compared to PFCAs with the same carbon number in the molecules. In contrast, the levels of long-chain PFAAs were comparatively lower than those of short-chain substances in the stem and leaf. Notably, PFAAs with less carbon numbers, like PFPeA, PFBA, and PFBS, showed a remarkable translocation from the root to the stem and leaf with TFs >1. For the whole plant, no significant correlation was found between BCFs and organic carbon-water partition coefficients (Koc), octanol-water partition coefficients (Kow), membrane-water distribution coefficients (Dmw), or protein-water distribution coefficients (Dpw). The removal rates of PFAAs ranged from 40.3 to 63.5 % throughout the three weeks of the experiment while the removal efficiencies varied from 48.9 % for PFHxS to 82.6 % for PFPeA in the last week.

Aluminum doped zinc oxide deposited by atomic layer deposition and its applications to micro/nano devices.

This work reports investigation on the deposition and evaluation of an aluminum-doped zinc oxide (AZO) thin film and its novel applications to micro- and nano-devices. The AZO thin film is deposited successfully by atomic layer deposition (ALD). 50 nm-thick AZO film with high uniformity is checked by scanning electron microscopy. The element composition of the deposited film with various aluminum dopant concentration is analyzed by energy-dispersive X-ray spectroscopy. In addition, a polycrystalline feature of the deposited film is confirmed by selected area electron diffraction and high-resolution transmission electron microscopy. The lowest sheet resistance of the deposited AZO film is found at 0.7 kΩ/□ with the aluminum dopant concentration at 5 at.%. A novel method employed the ALD in combination with the sacrificial silicon structures is proposed which opens the way to create the ultra-high aspect ratio AZO structures. Moreover, based on this finding, three kinds of micro- and nano-devices employing the deposited AZO thin film have been proposed and demonstrated. Firstly, nanowalled micro-hollows with an aspect ratio of 300 and a height of 15 µm are successfully produced . Secondly, micro- and nano-fluidics, including a hollow fluidic channel with a nanowall structure as a resonator and a fluidic capillary window as an optical modulator is proposed and demonstrated. Lastly, nanomechanical resonators consisting of a bridged nanobeam structure and a vertical nanomechanical capacitive resonator are fabricated and evaluated.

Micro-Fabricated Presure Sensor Using 50 nm-Thick of Pd-Based Metallic Glass Freestanding Membrane.

This paper reports on micro-fabricated pressure sensors based on a thin metallic glass membrane. The Pd66Cu4Si30 metallic glass material is deposited successfully by a sputter technique. An amorphous feature of the deposited film is confirmed by high resolution transmission electron microscopy (HR-TEM) and the corresponding the selected area electron diffraction (SAED). The ultra-flat freestanding metallic glass membrane with 50 nm in thickness and 2 mm in circular diameter has been fabricated successfully. In addition, two kinds of micro-fabricated pressure sensor types, including itself membrane and additional metallic glass bar as piezoresistive sensing elements, are proposed and fabricated. A displacement of membrane can reach over 100 µm without any damage to membrane which is equivalent to over 0.7% of an elastic strain. Besides, the temperature coefficient of resistance of the Pd-based metallic glass thin film is extremely low 9.6 × 10-6 °C-1. This development of nano-thick metallic glass membrane possibly opens a new field of micro-fabricated devices with large displacement and enhanced sensing.

Beyond monetary benefits of restoring sight in Vietnam: Evaluating well-being gains from cataract surgery.

A more holistic understanding of the benefits of sight-restoring cataract surgery requires a focus that goes beyond income and employment, to include a wider array of well-being measures. The objective of this study is to examine the monetary and non-monetary benefits of cataract surgery on both patients as well as their caregivers in Vietnam. Participants were randomly recruited from a Ho-Chi-Minh City Hospital. A total of 82 cataract patients and 83 caregivers participated in the survey conducted for this study. Paired t-tests, Wilcoxon Signed Rank tests, and regression analysis are used to detect any statistically significant differences in various measures of well-being for patients and caregivers before and after surgery. There are statistically significant improvements in monetary and non-monetary measures of well-being for both patients and caregivers approximately three months after undergoing cataract surgery, compared with baseline assessments collected prior to surgery. Non-monetary measures of well-being include self-assessments of overall health, mental health, hope, self-efficacy, happiness and life satisfaction. For patients, the benefits included statistically significant improvements in earnings, mobility, self-care, the ability to undertake daily activities, self-assessed health and mental health, life satisfaction, hope, and self-efficacy (p<0.01). For caregivers, attendance at work improved alongside overall health, mental health, hope, self-efficacy, happiness and life satisfaction, three months post-surgery (p<0.01). Restoring sight has positive impacts for those suffering from cataracts and their caregivers. Sometimes the benefits are almost equal in their magnitude. The study has also demonstrated that many of these impacts are non-monetary in nature. It is clear that estimates of the rate of return to restoring sight that focus only on financial gains will underestimate the true returns to society of restoring sight from cataract surgeries.

Blood and blood components used in hopitals at Ho Chi Minh City from 2001 to 2002

A retrospective study on the use of total blood and blood preparations from 2001 to November 2002 period was reported. 144,394 units of blood were used, among them, total blood accounts for 41.50%, sedimented red blood cells 31.25%, washed red blood cells 0.88%, fresh freezing plasma 4.60%, concentrated blood plaquettes 13.34%, fresh plasma intensified with white blood cells 4.17%, freezing precipitation with high rate of VIU factor 4.17%. A higher amount of total blood was used in comparing of that of the past year. High efficacy of the use of blood was toted