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1.
Sci Total Environ ; 798: 149289, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34340085

ABSTRACT

Reverse osmosis (RO) is being used in many water reclamation facilities to produce high quality water that can be reused for different purposes. As a part of the RO process, a reject stream is produced as the reverse osmosis concentrate (ROC), which contains elevated levels of contaminants compared to the source water. Effective treatment and safe disposal of ROC via cost-effective means is very challenging. This study aims to develop a robust microbubble ozonation-biological process for industrial ROC treatment with a target effluent chemical oxygen demand (COD) lower than 60 mg/L. As compared to macrobubble ozonation, microbubble ozonation exhibited better ozone dissolution and 29% higher COD removal efficiency with the same ozone dosage. Under the optimum operating conditions with ozone dosage of 30 mg/L, ROC natural pH of 8.67 and ozonation duration of 1 h, microbubble ozonation achieved 42% COD removal efficiency while increasing the BOD5/COD ratio (ratio of biological oxygen demand over 5 days to the corresponding chemical oxygen demand) in ROC from 0.042 to 0.216. A biological activated carbon (BAC) column with an empty bed contact time (EBCT) of 120 min was combined with microbubble ozonation for continuous ROC treatment. Over the 100-day operation, the combined system performed consistent organics removal with an average effluent COD of 45 mg/L. Both LC-OCD data and fluorescence EEM spectra confirmed humic substances were the dominant organic species in ROC. Ozone pre-treatment could achieve significant removal of humic substances in raw ROC. ATP analysis found that ozone pre-treatment enhanced BAC biofilm activity by around 5 folds. 5 min acute toxicity assessment with Aliivibrio fischeri showed 4 times reduction of bioluminescence inhibition in ozone treated ROC. From the environmental point of view, Life cycle assessment (LCA) results demonstrated that Ozone-BAC system had significant environmental burdens on climate change and human toxicity due to the electricity production process. These environmental impacts can be mitigated by optimizing the ozonation process with reduced ozone dosage or utilizing renewable energy sources for electricity generation.


Subject(s)
Ozone , Water Pollutants, Chemical , Charcoal , Environment , Humans , Microbubbles , Osmosis , Water Pollutants, Chemical/analysis
2.
Med J Malaysia ; 76(3): 414-416, 2021 05.
Article in English | MEDLINE | ID: mdl-34031342

ABSTRACT

Fluctuation of BCR-ABL1 real-time quantitative polymerase chain reaction in International Scale (qPCRIS) level below major molecular response (MMR) (0.1%IS) is a known phenomenon after stopping tyrosine kinase inhibitor (TKI) in chronic myeloid leukaemia (CML) patients who are attempting treatment free remission (TFR). We report here four cases of fluctuation beyond MMR during conduct of a Malaysia Stop TKI Trial (MSIT) to examine the validity of the commonly used relapse criterion - loss of MMR for one reading - aiming to provide evidence in setting relapse criteria for future CML patients who want to attempt TFR.


Subject(s)
Fusion Proteins, bcr-abl , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Fusion Proteins, bcr-abl/genetics , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Neoplasm Recurrence, Local , Protein Kinase Inhibitors/therapeutic use , Treatment Outcome
4.
Nature ; 586(7830): 538-542, 2020 10.
Article in English | MEDLINE | ID: mdl-33087912

ABSTRACT

Monolithic integration of control technologies for atomic systems is a promising route to the development of quantum computers and portable quantum sensors1-4. Trapped atomic ions form the basis of high-fidelity quantum information processors5,6 and high-accuracy optical clocks7. However, current implementations rely on free-space optics for ion control, which limits their portability and scalability. Here we demonstrate a surface-electrode ion-trap chip8,9 using integrated waveguides and grating couplers, which delivers all the wavelengths of light required for ionization, cooling, coherent operations and quantum state preparation and detection of Sr+ qubits. Laser light from violet to infrared is coupled onto the chip via an optical-fibre array, creating an inherently stable optical path, which we use to demonstrate qubit coherence that is resilient to platform vibrations. This demonstration of CMOS-compatible integrated photonic surface-trap fabrication, robust packaging and enhanced qubit coherence is a key advance in the development of portable trapped-ion quantum sensors and clocks, providing a way towards the complete, individual control of larger numbers of ions in quantum information processing systems.

5.
Br Dent J ; 228(11): 827, 2020 06.
Article in English | MEDLINE | ID: mdl-32541736
6.
Int J Oral Maxillofac Surg ; 47(12): 1609-1612, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29752202

ABSTRACT

Third molar extraction is a common procedure in dental surgery. Common complications that may occur post procedure include pain, trismus, bleeding, dry socket, and nerve injuries. Subcutaneous emphysema is an uncommon complication. A rare case of extensive cervicofacial subcutaneous emphysema, pneumomediastinum, and pneumorrhachis following third molar extraction is reported here. Issues relating to the diagnosis, aetiology, and management of these complications are discussed.


Subject(s)
Mediastinal Emphysema/etiology , Molar, Third/surgery , Pneumorrhachis/etiology , Subcutaneous Emphysema/etiology , Tooth Extraction , Tooth, Impacted/surgery , Adolescent , Humans , Male , Mediastinal Emphysema/diagnosis , Mediastinal Emphysema/therapy , Pneumorrhachis/diagnosis , Pneumorrhachis/therapy , Subcutaneous Emphysema/diagnosis , Subcutaneous Emphysema/therapy
7.
Colorectal Dis ; 19(1): O86-O89, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27943513

ABSTRACT

AIM: The purpose of this study was to evaluate one surgeon's initial experience with a novel technique of retroflexed endoscopic coagulation of internal haemorrhoids. METHOD: Patients who presented with symptoms and signs indicating Grade II-III haemorrhoids were counselled before the procedure. Those who were assessed to require an examination of their colon, based on their age and symptoms, underwent a full colonoscopy before treatment of the haemorrhoids. After the procedure, patients were routinely prescribed nonsteroidal anti-inflammatory drugs, antibiotics and laxatives. RESULTS: The first 100 patients of median age 52.0 (20.8-78.5) years included 65 (65%) women. Five (5%) patients suffered from postprocedural complications, of which three (3%) were postprocedural bleeding and two (2%) were postprocedural pain, all treated conservatively. The recurrence rate was 6% at a median follow-up time of 36 (6-76) months. The median duration of follow-up was 36.5 (8.5-57.0) months. CONCLUSION: This novel technique appears to be safe and effective for the treatment of Grade II-III internal haemorrhoids, and can be incorporated seamlessly into the end of a colonoscopy for the evaluation of haematochezia. Comparative trials should be performed.


Subject(s)
Colonoscopy/methods , Electrocoagulation/methods , Hemorrhoids/surgery , Adult , Aged , Colon/surgery , Female , Follow-Up Studies , Gastrointestinal Hemorrhage/epidemiology , Gastrointestinal Hemorrhage/etiology , Humans , Male , Middle Aged , Pain, Postoperative/epidemiology , Pain, Postoperative/etiology , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Rectum/surgery , Recurrence , Treatment Outcome , Young Adult
8.
Colloids Surf B Biointerfaces ; 147: 210-216, 2016 Nov 01.
Article in English | MEDLINE | ID: mdl-27518452

ABSTRACT

Lipases are key components in the mechanisms underlying the persistence and virulence of infections by fungi, and thus also promising triggers for bioresponsive lipid-based liquid crystalline nanoparticles. We here propose a platform in which only a minor component of the formulation is susceptible to cleavage by lipase and where hydrolysis triggers a controlled phase transition within the nanoparticles that can potentially allow for an extended drug release. The responsive formulations were composed of phytantriol, which was included as a non-cleavable major component and polysorbate 80, which serves both as nanoparticle stabilizer and potential lipase target. To monitor the structural changes resulting from lipase activity with sufficient time resolution, we used synchrotron small angle x-ray scattering. Comparing the effect of the two different lipases used in this work, lipase B from Candida Antarctica, (CALB) and lipase from Rhizomucor miehei (RMML), only CALB induced phase transition from bicontinuous reverse cubic to reverse hexagonal phase within the particles. This phase transition can be attributed to an increasing amount of oleic acid formed on cleavage of the polysorbate 80. However, when also a small amount of a cationic surfactant was included in the formulation, RMML could trigger the corresponding phase transition as well. The difference in activity between the two lipases can tentatively be explained by a difference in their interaction with the nanoparticle surface. Thus, a bioresponsive system for treating fungal infections, with a tunable selectivity for different types of lipases, could be obtained by tuning the composition of the nanoparticle formulation.


Subject(s)
Drug Liberation , Fungal Proteins/metabolism , Lipase/metabolism , Liquid Crystals/chemistry , Nanoparticles/chemistry , Fatty Alcohols/chemistry , Hydrolysis , Phase Transition , Polysorbates/metabolism , Rhizomucor/enzymology , Scattering, Small Angle , Surface Properties , Surface-Active Agents/chemistry , X-Ray Diffraction
9.
Allergy ; 70(8): 1020-3, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25951913

ABSTRACT

Anaphylaxis to galacto-oligosaccharides (GOS), a prebiotic, has been described in atopic patients following its supplementation in commercial milk formula in South-East Asia. The epidemiology of this usual allergy to a carbohydrate is unknown. This study evaluated the prevalence of allergy to two formulations of commercial GOS, Vivinal™ GOS (vGOS) and Oligomate™ , in an atopic cohort. Atopic subjects (n = 487) from two specialist allergy clinics were surveyed via structured questionnaire and underwent skin prick tests to GOS. Subjects with positive skin prick tests to GOS (n = 30, 6.2%) underwent basophil activation tests, and a subset (n = 13) underwent oral challenge tests to both formulations of GOS. Six subjects had positive challenges to vGOS; and none to Oligomate. By extrapolating the BAT and oral challenge results, the prevalence of allergy to vGOS is estimated at up to 3.5% (95% CI 2.2-5.5%) of our atopic population. Our findings show that GOS allergy may be common amongst atopics in Singapore.


Subject(s)
Anaphylaxis/epidemiology , Anaphylaxis/etiology , Hypersensitivity, Immediate/epidemiology , Hypersensitivity, Immediate/etiology , Oligosaccharides/adverse effects , Adolescent , Adult , Age Distribution , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Incidence , Male , Middle Aged , Oligosaccharides/administration & dosage , Prebiotics/administration & dosage , Prebiotics/adverse effects , Risk Assessment , Sex Distribution , Singapore/epidemiology , Skin Tests/methods , Young Adult
10.
Soft Matter ; 10(47): 9496-505, 2014 Dec 21.
Article in English | MEDLINE | ID: mdl-25347132

ABSTRACT

Recent studies have pointed out the importance of polyelectrolyte assembly in the elaboration of innovative nanomaterials. Beyond their structures, many important questions on the thermodynamics of association remain unanswered. Here, we investigate the complexation between poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium acrylate) (PANa) chains using a combination of three techniques: isothermal titration calorimetry (ITC), static and dynamic light scattering and electrophoresis. Upon addition of PDADMAC to PANa or vice-versa, the results obtained by the different techniques agree well with each other, and reveal a two-step process. The primary process is the formation of highly charged polyelectrolyte complexes of size 100 nm. The secondary process is the transition towards a coacervate phase made of rich and poor polymer droplets. The binding isotherms measured are accounted for using a phenomenological model that provides the thermodynamic parameters for each reaction. Small positive enthalpies and large positive entropies consistent with a counterion release scenario are found throughout this study. Furthermore, this work stresses the importance of the underestimated formulation pathway or mixing order in polyelectrolyte complexation.

11.
Geobiology ; 12(5): 406-23, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25039581

ABSTRACT

Symbiont-bearing and non-symbiotic marine bivalves were used as model organisms to establish biosignatures for the detection of distinctive symbioses in ancient bivalves. For this purpose, the isotopic composition of lipids (δ13C) and bulk organic shell matrix (δ13C, δ34S, δ15N) from shells of several thiotrophic, phototrophic, or non-symbiotic bivalves were compared (phototrophic: Fragum fragum, Fragum unedo, Tridacna maxima; thiotrophic: Codakia tigerina, Fimbria fimbriata, Anodontia sp.; non-symbiotic: Tapes dorsatus, Vasticardium vertebratum, Scutarcopagia sp.). ∆13C values of bulk organic shell matrices, most likely representing mainly original shell protein/chitin biomass, were depleted in thio- and phototrophic bivalves compared to non-symbiotic bivalves. As the bulk organic shell matrix also showed a major depletion of δ15N (down to -2.2 ‰) for thiotrophic bivalves, combined δ13C and δ15N values are useful to differentiate between thio-, phototrophic, and non-symbiotic lifestyles. However, the use of these isotopic signatures for the study of ancient bivalves is limited by the preservation of the bulk organic shell matrix in fossils. Substantial alteration was clearly shown by detailed microscopic analyses of fossil (late Pleistocene) T. maxima and Trachycardium lacunosum shell, demonstrating a severe loss of quantity and quality of bulk organic shell matrix with time. Likewise, the composition and δ13C-values of lipids from empty shells indicated that a large part of these compounds derived from prokaryotic decomposers. The use of lipids from ancient shells for the reconstruction of the bivalve's life style therefore appears to be restricted.


Subject(s)
Bivalvia/metabolism , Fossils , Light , Sulfur/metabolism , Animal Shells/chemistry , Animals , Carbon Isotopes/analysis , Lipids/analysis , Nitrogen Isotopes/analysis , Species Specificity , Sulfur Isotopes/analysis , Symbiosis
12.
J Fish Biol ; 85(2): 307-28, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24963726

ABSTRACT

The barcoding of mitochondrial cytochrome c oxidase subunit 1 (coI) gene was amplified and sequenced from 16 species of freshwater fishes found in Lake Wivenhoe (south-eastern Queensland, Australia) to support monitoring of reservoir fish populations, ecosystem function and water health. In this study, 630-650 bp sequences of the coI barcoding gene from 100 specimens representing 15 genera, 13 families and two subclasses of fishes allowed 14 of the 16 species to be identified and differentiated. The mean ± s.e. Kimura 2 parameter divergence within and between species was 0.52 ± 0.10 and 23.8 ± 2.20% respectively, indicating that barcodes can be used to discriminate most of the fish species accurately. The two terapontids, Amniataba percoides and Leiopotherapon unicolor, however, shared coI DNA sequences and could not be differentiated using this gene. A barcoding database was established and a qPCR assay was developed using coI sequences to identify and quantify proportional abundances of fish species in ichthyoplankton samples from Lake Wivenhoe. These methods provide a viable alternative to the time-consuming process of manually enumerating and identifying ichthyoplankton samples.


Subject(s)
DNA Barcoding, Taxonomic , Fishes/genetics , Plankton , Polymerase Chain Reaction/methods , Animals , Base Sequence , Electron Transport Complex IV/genetics , Lakes , Larva/genetics , Molecular Sequence Data , Phylogeny , Queensland , Species Specificity
13.
CPT Pharmacometrics Syst Pharmacol ; 3: e114, 2014 May 14.
Article in English | MEDLINE | ID: mdl-24827872

ABSTRACT

A systems pharmacology approach was undertaken to define and identify the proteins/genes significantly associated with clinical incidence and severity of drug-induced peripheral neuropathy (DIPN). Pharmacological networks of 234 DIPN drugs, their known targets (both intended and unintended), and the intermediator proteins/genes interacting with these drugs via their known targets were examined. A permutation test identified 230 DIPN-associated intermediators that were enriched with apoptosis and stress response genes. Neuropathy incidence and severity were curated from drug labels and literature and were used to build a predictive model of DIPN using a regression tree algorithm, based on the drug targets and their intermediators. DIPN drugs whose targets interacted with both v-myc avian myelocytomatosis viral oncogene homolog (MYC) and proliferating cell nuclear antigen-associated factor (PAF15) were associated with a neuropathy incidence of 38.1%, whereas drugs interacting only with MYC had an incidence of 2.9%. These results warrant further investigation in order to develop a predictive tool for the DIPN potential of a new drug.

14.
J Fish Biol ; 84(1): 163-77, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24383803

ABSTRACT

This study assessed the spawning activity of the threatened Australian lungfish Neoceratodus forsteri by measuring egg densities within the artificial habitat of a large impoundment (Lake Wivenhoe, Australia). Eggs were sampled (August to November 2009) from multiple locations across the impoundment, but occurred at highest densities in water shallower than 40 cm along shorelines with a dense cover of submerged terrestrial vegetation. The numbers of eggs declined over the study period and all samples were dominated by early developmental stages and high proportions of unviable eggs. The quality of the littoral spawning habitats declined over the study as flooded terrestrial grasses decomposed and filamentous algae coverage increased. Water temperatures at the spawning site exhibited extreme variations, ranging over 20·4° C in water shallower than 5 cm. Dissolved oxygen concentrations regularly declined to <1 mg l⁻¹ at 40 and 80 cm water depth. Spawning habitats utilised by N. forsteri within impoundments expose embryos to increased risk of desiccation or excessive submergence through water-level variations, and extremes in temperature and dissolved oxygen concentration that present numerous challenges for successful spawning and recruitment of N. forsteri in large impoundment environments.


Subject(s)
Fishes/physiology , Reproduction/physiology , Sexual Behavior, Animal/physiology , Animals , Ecosystem , Lakes , Ovum/physiology , Oxygen/analysis , Queensland , Temperature , Water/chemistry
15.
Phys Rev Lett ; 111(19): 197401, 2013 Nov 08.
Article in English | MEDLINE | ID: mdl-24266488

ABSTRACT

Exciton-exciton recombination in isolated semiconducting single-walled carbon nanotubes was studied using femtosecond transient absorption. Under sufficient excitation to saturate the optical absorption, we observed an abrupt transition between reaction- and diffusion-limited kinetics, arising from reactions between incoherent localized excitons with a finite probability of ~0.2 per encounter. This represents the first experimental observation of a crossover between classical and critical kinetics in a 1D coalescing random walk, which is a paradigm for the study of nonequilibrium systems.

16.
Infection ; 41(1): 237-41, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22930069

ABSTRACT

We present a case of hand infection caused by Mycobacterium chelonae. The patient was a 58-year-old woman with Type II diabetes mellitus and stage 4 chronic kidney disease. The infection occurred following a ferret bite and had not responded to oral antibiotics in the primary care setting. She developed signs of pyogenic flexor tenosynovitis of the index and middle fingers of her left hand. Laboratory parameters showed high C-reactive protein, raised erythrocyte sedimentation rate and leucocytosis. Ultrasound imaging confirmed the clinical diagnosis. Plain radiographs showed no osseous involvement. The infection was treated with surgical debridement and broad spectrum parenteral antibiotics. The intra-operative tissue specimens were initially negative on aerobic and anaerobic cultures. Following transient improvement of her inflammatory parameters and clinical signs, she developed a recurrence with added features of osteomyelitis of the index and middle finger metacarpal heads on repeat radiographs. A revision surgical debridement of the flexor tenosynovitis and osteomyelitis with specific long-term antibiotic cover has led to resolution of the infection. Extended cultures of the tissue specimens at the regional laboratory confirmed the causative organism to be M. chelonae. To our knowledge, this is the first reported case of M. chelonae infection resulting from a ferret bite. This case reminds us of the need for a high index of suspicion for infection with uncommon pathogens following animal bites, especially in patients with altered immune status.


Subject(s)
Bites and Stings/complications , Ferrets , Hand Injuries/etiology , Hand Injuries/microbiology , Mycobacterium Infections, Nontuberculous/complications , Mycobacterium chelonae , Animals , Female , Hand Injuries/diagnosis , Hand Injuries/therapy , Humans , Middle Aged , Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium Infections, Nontuberculous/therapy , Treatment Outcome
17.
Opt Express ; 20(21): 24030-7, 2012 Oct 08.
Article in English | MEDLINE | ID: mdl-23188370

ABSTRACT

We present for the first time an all-optical wavelength conversion (AOWC) scheme supporting modulation format independency without requiring phase matching. The new scheme is named "spoof" four wave mixing (SFWM) and in contrast to the well-known FWM theory, where the induced dynamic refractive index grating modulates photons to create a wave at a new frequency, the SFWM is different in that the dynamic refractive index grating is generated in a nonlinear Bragg Grating (BG) to excite additional reflective peaks at either side of the original BG bandgap in reflection spectrum. This fundamental difference enable the SFWM to avoid the intrinsic shortcoming of stringent phase matching required in the conventional FWM, and allows AOWC with modulation format transparency and ultrabroad conversion range, which may have great potential applications for next generation of all-optical networks.


Subject(s)
Computer Communication Networks/instrumentation , Optical Devices , Telecommunications/instrumentation , Equipment Design , Equipment Failure Analysis
18.
Opt Lett ; 36(23): 4662-4, 2011 Dec 01.
Article in English | MEDLINE | ID: mdl-22139276

ABSTRACT

We propose and demonstrate hydrophobic photonic crystal fibers (PCFs). A chemical surface treatment for making PCFs hydrophobic is introduced. This repels water from the holes of PCFs, so that their optical properties remain unchanged even when they are immersed in water. The combination of a hollow core and a water-repellent inner surface of the hydrophobic PCF provides an ultracompact dissolved-gas sensor element, which is demonstrated for the sensing of dissolved ammonia gas.

19.
J Fish Biol ; 79(1): 112-21, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21722114

ABSTRACT

Traditional visual diet analysis techniques were compared with DNA barcoding in juvenile herbivorous rabbitfish Siganus fuscescens collected in Moreton Bay, Australia, where at least six species of seagrass occur. The intergenic spacer trnH-psbA, suggested as the optimal gene for barcoding angiosperms, was used for the first time to identify the seagrass in fish guts. Four seagrass species and one alga were identified visually from gut contents; however, there was considerable uncertainty in visual identification with 38 of 40 fish having unidentifiable plant fragments in their gut. PCR and single-strand conformational polymorphism (SSCP) were able to discriminate three seagrass families from visually cryptic gut contents. While effective in identifying cryptic gut content to family level, this novel method is likely to be most efficient when paired with visual identification techniques.


Subject(s)
DNA Barcoding, Taxonomic , DNA, Plant/analysis , Fishes , Zosteraceae/genetics , Animals , DNA, Ribosomal Spacer/analysis , Diet , Gastrointestinal Contents , Phylogeny , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational , Species Specificity
20.
Orthop Traumatol Surg Res ; 97(4): 451-3, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21511554

ABSTRACT

Anterior dislocation of shoulder is usually amenable to closed manipulation. Failure to achieve satisfactory reduction can be due to soft tissue or osseous interposition. We report a case of irreducible anterior shoulder dislocation with the interposition of the musculocutaneous nerve. This required open reduction and release of the musculocutaneous nerve; which was found to be further trapped by the torn long head of biceps.


Subject(s)
Manipulation, Orthopedic/adverse effects , Musculocutaneous Nerve/surgery , Orthopedic Procedures/methods , Shoulder Dislocation/therapy , Shoulder Joint/surgery , Soft Tissue Injuries/surgery , Accidental Falls , Follow-Up Studies , Humans , Ligaments, Articular/injuries , Ligaments, Articular/surgery , Male , Manipulation, Orthopedic/methods , Middle Aged , Multiple Trauma/diagnostic imaging , Multiple Trauma/surgery , Musculocutaneous Nerve/injuries , Nerve Regeneration/physiology , Radiography , Recovery of Function , Shoulder Dislocation/diagnostic imaging , Shoulder Injuries , Shoulder Joint/diagnostic imaging , Soft Tissue Injuries/diagnostic imaging , Treatment Failure , Treatment Outcome
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