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•Carbons surface charge contributes in a greater extend to arsenic (V) uptake.•Iron increases the As(V) adsorption capacity and promotes strong bonds Fe–O–As.•Adsorption capacity ...correlates with pHPZC and iron content.•As(V) adsorption is governed by OH-ligand exchange and electrostatic interactions.
Due to the high number of toxicological issues, the presence of asenic (V) in water supplies is a major problem of public concern. Adsorption by iron modified activated carbons stands as an interesting alternative for the removal of arsenic (V) from aqueous solutions. However, the question of which of the activated carbon properties have impact during arsenic (V) uptake has arisen. The influence of textural and chemical features of several activated carbons (AC), un-modified and modified with iron oxyhydroxide nanoparticles, for the removal of arsenic (V) from aqueous solution was studied. The surface area (SBET), micropore volume, surface charge and iron content of 28 ACs were determined. Results showed that the SBET of materials range from 388 to 1747 m2/g, the point of zero charge (PHPZC) from 3 to 11 and the iron content range from negligible to around 2%. A detailed data analysis demonstrated that the most important parameter of AC when removing arsenic (V) from water is the pHPZC (52.5% of contribution); however, the presence of iron is indispensable for enhancing the adsorption capacity (by 36.5%). An empirical model indicated that in order to effectively remove arsenic from water a basic AC with an iron content of about 1% is desirable. Arsenic (V) adsorption isotherms under normal conditions demonstrated that the materials studied have a great potential for water polishing. Finally it is suggested that the arsenate uptake by iron-modified AC is conducted by two simultaneous mechanisms: ligand interchange with iron oxyhydroxide particles and electrostatic attraction on basic AC.
Degenerative disc disease may cause severe low-back pain, a large public health problem with significant economic and life quality impact. Chronic cases often require surgery, which may lead to ...biomechanical problems and accelerated degeneration of the adjacent segments. Cell-based therapies may circumvent these problems and have exhibited encouraging results in vitro and in animal studies. We designed a pilot study to assess feasibility and safety and to obtain early indications on efficacy of treatment with mesenchymal stem cells (MSC) in humans.
Ten patients with chronic back pain diagnosed with lumbar disc degeneration with intact annulus fibrosus were treated with autologous expanded bone marrow MSC injected into the nucleus pulposus area. Clinical evolution was followed for 1 year and included evaluation of back pain, disability, and quality of life. Magnetic resonance imaging measurements of disc height and fluid content were also performed.
Feasibility and safety were confirmed and strong indications of clinical efficacy identified. Patients exhibited rapid improvement of pain and disability (85% of maximum in 3 months) that approached 71% of optimal efficacy. This outcome compares favorably with the results of other procedures such as spinal fusion or total disc replacement. Although disc height was not recovered, water content was significantly elevated at 12 months.
MSC therapy may be a valid alternative treatment for chronic back pain caused by degenerative disc disease. Advantages over current gold standards include simpler and more conservative intervention without surgery, preservation of normal biomechanics, and same or better pain relief.
Composites of magnetite and two-line ferrihydrite with graphite oxide (GO) were synthesized and tested as hydrogen sulfide adsorbents. Exhausted and initial composites were characterized by the ...adsorption of nitrogen, X-ray diffraction, potentiometric titration, thermal analysis, and FTIR. The addition of GO increased the surface area of the composites due to the formation of new micropores. The extent of the increase depended on the nature of the iron (hydr)oxide and the content of GO. The addition of GO did not considerably change the crystal structure but increased the number of acidic functional groups. While for the magnetite composites an increase in the H2S adsorption capacity after GO addition was found, the opposite effect was recorded for the ferrihydrite composites. That increase in the adsorption capacity was linked to the affinity of the composites to adsorb water in mesopores of specific sizes in which the reaction with basic surface groups takes place. Elemental sulfur and ferric and ferrous sulfates were detected on the surface of the exhausted samples. A redox reactive adsorption mechanism is proposed to govern the retention of hydrogen sulfide on the surface of the composites. The incorporation of GO enhances the chemical retention of H2S due to the incorporation of OH reactive groups and an increase in surface heterogeneity.
Surface electromyography (sEMG) can be helpful for evaluating swallowing related muscle activity. Conventional recordings with disc electrodes suffer from significant crosstalk from adjacent muscles ...and electrode-to-muscle fiber orientation problems, while concentric ring electrodes (CREs) offer enhanced spatial selectivity and axial isotropy. The aim of this work was to evaluate CRE performance in sEMG recordings of the swallowing muscles. Bipolar recordings were taken from 21 healthy young volunteers when swallowing saliva, water and yogurt, first with a conventional disc and then with a CRE. The signals were characterized by the root-mean-square amplitude, signal-to-noise ratio, myopulse, zero-crossings, median frequency, bandwidth and bilateral muscle cross-correlations. The results showed that CREs have advantages in the sEMG analysis of swallowing muscles, including enhanced spatial selectivity and the associated reduction in crosstalk, the ability to pick up a wider range of EMG frequency components and easier electrode placement thanks to its radial symmetry. However, technical changes are recommended in the future to ensure that the lower CRE signal amplitude does not significantly affect its quality. CREs show great potential for improving the clinical monitoring and evaluation of swallowing muscle activity. Future work on pathological subjects will assess the possible advantages of CREs in dysphagia monitoring and diagnosis.
Six extant species of non-human great apes are currently recognized: Sumatran and Bornean orangutans, eastern and western gorillas, and chimpanzees and bonobos 1. However, large gaps remain in our ...knowledge of fine-scale variation in hominoid morphology, behavior, and genetics, and aspects of great ape taxonomy remain in flux. This is particularly true for orangutans (genus: Pongo), the only Asian great apes and phylogenetically our most distant relatives among extant hominids 1. Designation of Bornean and Sumatran orangutans, P. pygmaeus (Linnaeus 1760) and P. abelii (Lesson 1827), as distinct species occurred in 2001 1, 2. Here, we show that an isolated population from Batang Toru, at the southernmost range limit of extant Sumatran orangutans south of Lake Toba, is distinct from other northern Sumatran and Bornean populations. By comparing cranio-mandibular and dental characters of an orangutan killed in a human-animal conflict to those of 33 adult male orangutans of a similar developmental stage, we found consistent differences between the Batang Toru individual and other extant Ponginae. Our analyses of 37 orangutan genomes provided a second line of evidence. Model-based approaches revealed that the deepest split in the evolutionary history of extant orangutans occurred ∼3.38 mya between the Batang Toru population and those to the north of Lake Toba, whereas both currently recognized species separated much later, about 674 kya. Our combined analyses support a new classification of orangutans into three extant species. The new species, Pongo tapanuliensis, encompasses the Batang Toru population, of which fewer than 800 individuals survive.
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•We describe a new species of great apes, the Tapanuli orangutan Pongo tapanuliensis•Genomic analyses corroborate morphological distinctiveness of P. tapanuliensis•P. tapanuliensis comprises the oldest evolutionary lineage in the genus Pongo•With fewer than 800 individuals, P. tapanuliensis is among the most endangered great apes
Nater et al. describe a new great ape species, the Tapanuli orangutan Pongo tapanuliensis. An isolated population from Batang Toru is highly distinct from the northern Sumatran and Bornean species, based on morphological variation, corroborated by population genomic analyses. Fewer than 800 individuals of P. tapanuliensis survive in the wild.
Mixed perovskites have vast industrial potential, but some challenges (
i.e.
, aggregation and chemical instability) limit their applications. Herein, a novel environment-friendly carbon aerogel ...(CAg) synthesized from sodium alginate (SA) was used as a precursor to create a double-B-site perovskite/carbon aerogel hybrid adsorbent ((Sr
0.7
Mn
0.3
Co
0.5
Fe
0.5
O
3−
δ
)/CAg) (DB-perovskite/CAg hybrid). The adsorbent was extensively characterized
via
different techniques, including X-ray photoelectron spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The removal efficiency for crystal violet (CV) and acid yellow 17 (AY17) was conducted over various pH, adsorbent/adsorbate dosages, and reaction times in an aqueous system. The maximum adsorbed concentration (
Q
max
) recorded by 206 mg g
−1
and 113 mg g
−1
for CV and AY17, respectively, and compared to the performance of only DB-perovskite (114 mg g
−1
and 59 mg g
−1
), respectively. The adsorption site energy distribution was studied by applying the density functional theory (DFT). The adsorption on the DB-perovskite/CAg hybrid was significantly regulated by pH change. The cooperative metal active/Lewis acid sites of the DB-perovskite/CAg adsorbent led to a faster and higher adsorption capacity toward CV and AY 17. The doping of Mn indicated a synergistic effect in improving the adsorption of either dye through the introduction of abundant active sites and strengthening of metal-functional groups (-C-O-C, -COOH, and C-OH/O-H)-π aromatic bonding, confirmed by DFT calculations.
Rational design of a double perovskite-carbon composite with multifarious active sites for the removal of dyes from aqueous solution.
Anthracene belongs to the polycyclic aromatic hydrocarbon (PAH) consisting of benzene rings, unusually highly stable through more π-electrons and localized π-bond in entire rings. Aqueous-phase ...anthracene adsorption using carbon-based materials such as biochar is ineffective. In this paper, carbon dots (CDs) derived from the acid treatment of coconut shell biochar (CDs/MCSB) decorated with chitosan (CS) are successfully synthesized and applied for anthracene removal from aqueous solutions. The h-CDs/MCSB exhibited fast adsorption of anthracene with significant sorption capacity (Qmax = 49.26 mg g−1) with 95 % removal efficiency at 60 min. The study suggested chemisorption dominated monolayer anthracene adsorption onto h-CDs/MCSB, where a significant role was played by ion-exchange. Density Functional Theory (DFT) suggested the anthracene adsorption was dominated by the electrostatic interactions and delocalized electron, induced by higher polarizability of functional groups on the surface of hybrid CDs/MCSB assisted by chitosan (h-CDs/MCSB). In addition, the aromatic structure of CDs/MCSB and high polarizability of functional groups provided the strong interactions between benzene rings of anthracene and hybrid adsorbent-assisted multiple π-bond through delocalized π-bond and polarization-induced H-bond interactions. The presence of carboxylic and sulfonic groups on the CDs/MCSB surface also contributed to the effective adsorption of anthracene was confirmed by the fluorescence spectra. The results showed that the hybrid adsorbent was an effective material for removing PAHs, usually difficult to remove from water owing to the presence of benzene rings in their structures. Further, consistency in the DFT results suggested the outstanding binding capacity with the anthracene molecules with h-CDs/MCSB.
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•Enhanced anthracene adsorption using carbon dots decorated chitosan (CDs/MCSB).•CDs/MCSB showed highly polarized functional groups and delocalized surface energy.•Consistency of the DFT study revealed significant removal efficiency for PAHs.
In this work, novel composites of iron hydroxide and graphite oxide (GO), initial or modified with urea, were synthesized and used as media for a 2-chloroethyl ethyl sulfide (CEES) ...removal/decontamination process. The results of surface characterization, using various physical and chemical methods, indicated that oxygen groups in GO act as nucleation centers for the hydrous ferric oxide formation/aggregation. Addition of the graphene phase increased the surface area and the amount of reactive adsorption centers. The iron hydroxide particles were highly dispersed between and on the graphene layers. Mesoporous 2 and 6-line ferrihydrites with a surface area higher than 200 m super(2) g super(-1) were identified as the main inorganic phase of the composites. An alteration in the optical band gap was found, depending on the chemical properties of the graphite oxide. The composites demonstrated a marked CEES adsorption capacity and outperformed the unmodified iron hydroxide. Visible light enhanced the removal of CEES owing to its photocatalytic properties. As a result of this, CEES degradation products migrate to very small pores of the composites, releasing the adsorption centers for further reactive adsorption of the CEES molecules.
Poly(phenylenevinylene)‐based organic light‐emitting diodes (OLEDs) are fabricated using air‐stable metal oxides as electrodes, producing very efficient and bright electroluminescent devices. ...Efficiencies of 8 cd A−1 and luminances above 20000 cd m−2 are obtained, comparable to the values reported for classic OLED structures using reactive metals as cathodes.
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