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Fulltext Niches, body sizes, and the disassembly of mammal communities on the Sunda Shelf islands

Okie JG, Brown JH

Proc Natl Acad Sci U S A, 2009 Nov 17;106 Suppl 2:19679-84.
PMID: 19805179 DOI: 10.1073/pnas.0901654106

The rising sea level at the end of the Pleistocene that created the islands of the Sunda Shelf in Indonesia and Malaysia provides a natural experiment in community disassembly and offers insights into the effects of body size and niches on abundance, distribution, and diversity. Since isolation, terrestrial mammal communities of these islands have been reduced by extinction, with virtually no offsetting colonization. We document three empirical patterns of disassembly, all of which are significantly different from null models of random assembly: (i) a diversity-area relationship: the number of taxa is strongly and positively correlated with island area; (ii) nested subset composition: species that occur on small islands tend to be subsets of more diverse communities inhabiting larger islands; and (iii) body size distributions: species of intermediate body sizes occur on the greatest number of islands, and smaller islands have smaller ranges of body sizes, caused by the absence of species of both very large and extremely small size. These patterns reveal the role of body size and other niche characteristics, such as habitat requirements and trophic status, in the differential susceptibility of taxa to extinction.
Impact of mycolactone produced by Mycobacterium ulcerans on life-history traits of Aedes aegypti (L.) and resulting habitat selection for oviposition

Mashlawi AM, Jordan HR, Crippen LT, Tomberlin JK

Trop Biomed, 2020 Dec 01;37(4):973-985.
PMID: 33612750 DOI: 10.47665/tb.37.4.973

Buruli ulcer (BU) is a globally recognized, yet largely neglected tropical disease whose etiologic agent is Mycobacterium ulcerans. Although the exact mode of transmission is unclear, epidemiological evidence links BU incidence with slow-moving or stagnant, aquatic habitats, and laboratory-based experiments have shown disease manifestation in animals with dermal punctures. Therefore, hypotheses for transmission include contact with slowmoving aquatic habitats and associated biting aquatic insects, such as mosquitoes. Recent research demonstrated the toxin produced by M. ulcerans, mycolactone, is an attractant for adult mosquitoes seeking a blood-meal as well as oviposition sites. In the study presented here, we examined the impact of mycolactone at different concentrations on immature lifehistory traits of Aedes aegypti, which commonly occurs in the same environment as M. ulcerans. We determined percent egg hatch was not significantly different across treatments. However, concentration impacted the survivorship of larval mosquitoes to the adult stage (p < 0.001). Resulting adults also showed a slight preference, but not significant (p > 0.05), for oviposition in habitats contaminated with mycolactone suggesting a legacy effect.
Lung health in LMICs: tackling challenges ahead

Khoo EM, Li D, Ungan M, Jordan R, Pinnock H

Lancet, 2021 08 07;398(10299):488-489.
PMID: 34364520 DOI: 10.1016/S0140-6736(21)01230-7
Treatment for diabetic ulcer wounds using a fern tannin optimized hydrogel formulation with antibacterial and antioxidative properties

Lai JC, Lai HY, Nalamolu KR, Ng SF

J Ethnopharmacol, 2016 08 02;189:277-89.
PMID: 27208868 DOI: 10.1016/j.jep.2016.05.032

ETHNOPHARMACOLOGICAL RELEVANCE: Blechnum orientale Linn. (B. orientale) is a fern traditionally used by the natives as a poultice to treat wounds, boils, ulcers, blisters, abscesses, and sores on the skin.
AIM OF THE STUDY: To investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds.
MATERIALS AND METHODS: The water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey's T-test (P<0.05).
RESULTS: One fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5-1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis.
CONCLUSION: The ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.
Experimental Amelioration of Harsh Weather Speeds Growth and Development in a Tropical Montane Songbird

Mitchell AE, Boersma J, Anthony A, Kitayama K, Martin TE

Am Nat, 2020 10;196(4):E110-E118.
PMID: 32970467 DOI: 10.1086/710151

AbstractOrganisms living at high elevations generally grow and develop more slowly than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improves juvenile quality via physiological trade-offs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for mountain blackeyes (Chlorocharis emiliae), a montane songbird living at approximately 3,200 m asl in Malaysian Borneo. This experiment was designed to test whether cold and wet montane conditions contribute to parental care and postnatal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared with offspring from unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents and offspring. These plastic responses highlight the importance of proximate weather contributions to broad patterns of montane ontogeny and parental care.
Fulltext Pink Pigmented Facultative Methylotrophic Bacteria Isolated from Fermented Philippine Shrimp Paste

Dela Rosa CJO, Lee AC, Rivera WL

Trop Life Sci Res, 2021 Jun;32(2):147-161.
PMID: 34367520 DOI: 10.21315/tlsr2021.32.2.10

Pink pigmented facultative methylotrophic (PPFM) bacteria are ecologically distributed microorganisms. They have been isolated in many types of ecosystems like soil, water, air, in association with plants and even as pathogens in humans. However, a yet unexplored area for PPFM bacteria research is in food. Hence, the objective of this study was to establish the presence of PPFM bacteria in Philippine fermented food, in particular shrimp paste, and characterise them phenotypically and genotypically. A total of 13 PPFM bacteria were obtained from Philippine shrimp paste. Sequencing of the 16S rRNA gene revealed that the PPFM bacterial isolates belong to the genus Methylobacterium. A total of 35 phenotypic characterisations were performed that included morphological, biochemical and physiological tests. Phylogenetic tree was constructed to establish the genetic relatedness of the isolates. Morphological test results showed that all 13 isolates were consistent with the established phenotypic characters of the genus such as pink colony colour, Gram negative and rod-shaped. Biochemically, the use of API® 20 NE tests showed heterogeneity of results and physiological tests exhibited that the isolates are primarily mesophilic and halotolerant, being able to grow at 2% salt. Phylogenetic analysis showed that the isolates are Methylobacterium populi, M. dankookense, M. lusitanum, M. radiotolerans and M. zatmanii. This study confirmed the presence and diversity of PPFM bacteria in Philippine shrimp paste. Further studies are needed to show the functional activity of Methylobacterium in Philippine shrimp paste production.
Fulltext Giant cell tumor of temporomandibular joint masquerading as temporomandibular joint pain dysfunction syndrome: a rare case report

Sam JE, Rachmat RPN, Melano CSJ, Wahab NA

J Korean Assoc Oral Maxillofac Surg, 2017 Apr;43(2):134-137.
PMID: 28462199 DOI: 10.5125/jkaoms.2017.43.2.134

Giant cell tumor (GCT) of the craniofacial bones has been reported but they are not common. This tumor occurs more often in women than in men and predominantly affects patients around the third to fifth decade of life. GCTs are generally benign but can be locally aggressive as well. We report a case of GCT involving the temporomandibular joint (TMJ), which was initially thought to be temporomandibular disorder (TMD). A 22-year-old female presented with swelling and pain over the right temporal region for 18 months associated with jaw locking and clicking sounds. On examination, her jaw deviated to the right during opening and there was a 2×2 cm swelling over the right temporal region. Despite routine treatment for TMD, the swelling increased in size. Computed tomography and magnetic resonance imaging of the brain and TMJ revealed an erosive tumor of the temporal bone involving the TMJ which was displacing the temporal lobe. Surgical excision was done and the tumor removed completely. Histopathological examination was consistent with a GCT. No clinical or radiological recurrence was detected 10 months post-surgery.

Study site: Hospital Pulau Pinang
Membrane-lytic actions of sulphonated methyl ester surfactants and implications to bactericidal effect and cytotoxicity

Pan F, Li Z, Gong H, Petkov JT, Lu JR

J Colloid Interface Sci, 2018 Dec 01;531:18-27.
PMID: 30015167 DOI: 10.1016/j.jcis.2018.07.031

Surfactants are multifunctional molecules widely used in personal care and healthcare formulations to cleanse, help disperse active ingredients (e.g., forming emulsions) and stabilise products. With increasing demands on improving biosafety, there is now mounting pressure to understand how different surfactants elicit toxicities at molecular and cellular levels. This work reports the membrane-lytic behaviour of a group of sulphonated methyl ester (SME) surfactants together with representative conventional surfactants. All surfactants displayed the clear rise of lysis of the model lipid bilayer membranes around their CMCs, but the two ionic surfactants SDS and C12TAB even caused measurable lysis below their CMCs, with membrane-lytic actions increasing with monomer concentration. Furthermore, whilst ionic and nonionic surfactants could achieve full membrane lysis once above their CMCs, this ability was weak from the SME surfactants and decreased with increasing the acyl chain length. In contrast to the conventional anionic surfactants such as SDS and SLES, the protein solubilizing capability of the SME surfactants was also low. On the other hand, MTT assays against 3T3 fibroblast cells and human chondrocyte cells revealed high toxicity from SDS and C12TAB against the other surfactants studied, but the difference between SME and the rest of conventional surfactants was small. Similar behaviour was also observed in their bactericidal effect against E. coli and S. aureus. The trend is broadly consistent with their membrane-lytic behaviour, indicating little selectivity in their cytotoxicity and bactericidal action. These results thus reveal different toxicities implicated from different surfactant head groups. Increase in acyl chain length as observed from SME surfactants could help improve surfactant biocompatibility.
Spin is Prevalent in the Abstracts of Systematic Reviews and Meta-Analyses Comparing Biceps Tenodesis and Tenotomy Outcomes

Khaled K, Alderhali R, Helbing J, Alzobi O, Zikria B

Int Orthop, 2025 Jan 24.
PMID: 39853426 DOI: 10.1007/s00264-025-06414-6

PURPOSE: This study aimed to assess the presence of spin in abstracts of systematic reviews and meta-analyses comparing biceps tenodesis and tenotomy outcomes and to explore associations between spin and specific study characteristics.
METHODS: Using Web of Science and PubMed databases, systematic reviews and meta-analyses comparing outcomes of biceps tenodesis and tenotomy were identified. Abstracts were evaluated for the nine most severe types of spin as described by Yavchitz et al. and appraised using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Study characteristics were extracted, including adherence to PRISMA guidelines,funding status, and impact metrics such as journal impact factor, total number of citations, and average annual citations.
RESULTS: A total of 16 studies were included, with spin detected in 81.3% of the abstracts. Type three spin was the most frequent (56.3%), followed by types six (43.8%), five (37.5%), nine (25.0%), two (12.5%), and four (6.3%). Spin types one, seven, and eight were not observed. AMSTAR 2 appraised 75% of the studies as 'low' quality, and 25% as 'critically low' quality. All studies had at least one critical flaw, with item 15 (investigation of publication bias) being the most frequent (93.8%). A strong positive correlation was found between AMSTAR 2 scores and citation counts (r = 0.821, p
Fulltext Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification

Jafari SM, Jordan TJ, Distefano G, Bradley DA, Spyrou NM, Nisbet A, et al.

Br J Radiol, 2015;88(1055):20140804.
PMID: 26258442 DOI: 10.1259/bjr.20140804

To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification.
Fulltext Hard rock landforms generate 130 km ice shelf channels through water focusing in basal corrugations

Jeofry H, Ross N, Le Brocq A, Graham AGC, Li J, Gogineni P, et al.

Nat Commun, 2018 11 01;9(1):4576.
PMID: 30385741 DOI: 10.1038/s41467-018-06679-z

Satellite imagery reveals flowstripes on Foundation Ice Stream parallel to ice flow, and meandering features on the ice-shelf that cross-cut ice flow and are thought to be formed by water exiting a well-organised subglacial system. Here, ice-penetrating radar data show flow-parallel hard-bed landforms beneath the grounded ice, and channels incised upwards into the ice shelf beneath meandering surface channels. As the ice transitions to flotation, the ice shelf incorporates a corrugation resulting from the landforms. Radar reveals the presence of subglacial water alongside the landforms, indicating a well-organised drainage system in which water exits the ice sheet as a point source, mixes with cavity water and incises upwards into a corrugation peak, accentuating the corrugation downstream. Hard-bedded landforms influence both subglacial hydrology and ice-shelf structure and, as they are known to be widespread on formerly glaciated terrain, their influence on the ice-sheet-shelf transition could be more widespread than thought previously.
Fulltext Genetic diversity of Eurycoma longifolia inferred from single nucleotide polymorphisms

Osman A, Jordan B, Lessard PA, Muhammad N, Haron MR, Riffin NM, et al.

Plant Physiol, 2003 Mar;131(3):1294-301.
PMID: 12644679 DOI: 10.1104/pp.012492

Eurycoma longifolia Jack. is a treelet that grows in the forests of Southeast Asia and is widely used throughout the region because of its reported medicinal properties. Widespread harvesting of wild-grown trees has led to rapid thinning of natural populations, causing a potential decrease in genetic diversity among E. longifolia. Suitable genetic markers would be very useful for propagation and breeding programs to support conservation of this species, although no such markers currently exist. To meet this need, we have applied a genome complexity reduction strategy to identify a series of single nucleotide polymorphisms (SNPs) within the genomes of several E. longifolia accessions. We have found that the occurrence of these SNPs reflects the geographic origins of individual plants and can distinguish different natural populations. This work demonstrates the rapid development of molecular genetic markers in species for which little or no genomic sequence information is available. The SNP markers that we have developed in this study will also be useful for identifying genetic fingerprints that correlate with other properties of E. longifolia, such as high regenerability or the appearance of bioactive metabolites.
Fulltext Peer mentoring among undergraduate medical students: experience from Universiti Malaysia Sarawak

Cheah, Whye Lian, Helmy Nazmi, Hoo, Jordan Ching Bing, Chew, Jia Ying, Nurul Nazleatul Nadira Mohd Nazif, Siti Nurva'ain Mohd Kamil

Education in Medicine Journal, 2015;7(1):45-54.
MyJurnal

Introduction: Peer mentoring is one of the mentoring essential components in any higher institution of learning. In the Medical Faculty of Universiti Malaysia Sarawak (UNIMAS), this mentoring system has existed long but has not undergone any formal evaluation. Objective: The main objective of this study is to determine the perception of peer mentoring among medical students of Faculty of Medicine and Health Sciences (FMHS), UNIMAS. Method: It was a cross-sectional study using self-administered questionnaire. All medical undergraduate students of FMHS were recruited. Data was analyzed using SPSS version 22. Result: A total of 234 respondents participated in this study. Peer mentoring system was preferred against other mentoring system. Majority of the respondents reported that academic gain was the main benefits they gained from peer mentoring system. Negative attitude of the mentee and poor time management for the meeting were the top two worst experience encountered by both mentors and mentees respectively. More than half of the mentor and mentee perceived that peer mentoring system was beneficial to them compared to other systems, with reason that the interaction between student themselves were more easier and comfortable. Nevertheless, there should be more interaction between the mentors and mentees. Conclusion: The findings indicated there is a positive contribution of peer mentoring towards the mentoring system of the faculty. There is a need to relook at the current mentoring system and consider peer mentoring to improve the student support.
Exploration of the impact of a voice activated decision support system (VADSS) with video on resuscitation performance by lay rescuers during simulated cardiopulmonary arrest

Hunt EA, Heine M, Shilkofski NS, Bradshaw JH, Nelson-McMillan K, Duval-Arnould J, et al.

Emerg Med J, 2015 Mar;32(3):189-94.
PMID: 24243484 DOI: 10.1136/emermed-2013-202867

AIM: To assess whether access to a voice activated decision support system (VADSS) containing video clips demonstrating resuscitation manoeuvres was associated with increased compliance with American Heart Association Basic Life Support (AHA BLS) guidelines.
METHODS: This was a prospective, randomised controlled trial. Subjects with no recent clinical experience were randomised to the VADSS or control group and participated in a 5-min simulated out-of-hospital cardiopulmonary arrest with another 'bystander'. Data on performance for predefined outcome measures based on the AHA BLS guidelines were abstracted from videos and the simulator log.
RESULTS: 31 subjects were enrolled (VADSS 16 vs control 15), with no significant differences in baseline characteristics. Study subjects in the VADSS were more likely to direct the bystander to: (1) perform compressions to ventilations at the correct ratio of 30:2 (VADSS 15/16 (94%) vs control 4/15 (27%), p=<0.001) and (2) insist the bystander switch compressor versus ventilator roles after 2 min (VADSS 12/16 (75%) vs control 2/15 (13%), p=0.001). The VADSS group took longer to initiate chest compressions than the control group: VADSS 159.5 (±53) s versus control 78.2 (±20) s, p<0.001. Mean no-flow fractions were very high in both groups: VADSS 72.2% (±0.1) versus control 75.4 (±8.0), p=0.35.
CONCLUSIONS: The use of an audio and video assisted decision support system during a simulated out-of-hospital cardiopulmonary arrest prompted lay rescuers to follow cardiopulmonary resuscitation (CPR) guidelines but was also associated with an unacceptable delay to starting chest compressions. Future studies should explore: (1) if video is synergistic to audio prompts, (2) how mobile technologies may be leveraged to spread CPR decision support and (3) usability testing to avoid unintended consequences.
KEYWORDS: cardiac arrest; research, operational; resuscitation; resuscitation, effectiveness; resuscitation, research
Sulfonated methyl esters of fatty acids in aqueous solutions: Interfacial and micellar properties

Danov KD, Stanimirova RD, Kralchevsky PA, Basheva ES, Ivanova VI, Petkov JT

J Colloid Interface Sci, 2015 Nov 1;457:307-18.
PMID: 26196714 DOI: 10.1016/j.jcis.2015.07.020

The interest to sulfonated methyl esters of fatty acids (SME) has been growing during the last decade, because these surfactants are considered as an environmentally friendly and renewable alternative of the linear alkyl-benzene sulfonates (LAS). Here, we present a quantitative study on the properties of aqueous SME solutions, and especially on their surface tension isotherms, critical micelle concentration (CMC) and its dependence on the concentration of added NaCl. It is demonstrated that the CMC of an ionic surfactant determined by electrical conductivity is insensitive to the presence of a small nonionic admixture, so that the CMC values determined by conductivity represent the CMC of the pure surfactant. Using SME as an example, we have demonstrated the application of a new and powerful method for determining the physicochemical parameters of the pure ionic surfactant by theoretical data analysis ("computer purification") if the used surfactant sample contains nonionic admixtures, which are present as a rule. This method involves fits of the experimental data for surface tension and conductivity by a physicochemical model based on a system of mass-balance, chemical-equilibrium and electric-double-layer equations, which allows us to determine the adsorption and micellization parameters of C12-, C14-, C16- and C18-SME, as well the fraction of nonionic admixtures (if any). Having determined these parameters, we can further predict the interfacial and micellization properties of the surfactant solutions, such as surface tension, adsorption, degree of counterion binding, and surface electric potential at every surfactant, salt and co-surfactant concentrations.
Fulltext Properties of the micelles of sulfonated methyl esters determined from the stepwise thinning of foam films and by rheological measurements

Basheva ES, Danov KD, Radulova GM, Kralchevsky PA, Xu H, Ung YW, et al.

J Colloid Interface Sci, 2019 Mar 07;538:660-670.
PMID: 30572230 DOI: 10.1016/j.jcis.2018.12.034

HYPOTHESES: The micellar solutions of sulfonated methyl esters (SME) are expected to form stratifying foam films that exhibit stepwise thinning. From the height of the steps, which are engendered by micellar layers confined in the films, we could determine the micelle aggregation number, surface electric potential, and ionization degree. Moreover, addition of the zwitterionic surfactant cocamidopropyl betaine (CAPB) is expected to transform the small spherical micelles of SME into giant wormlike aggregates.
EXPERIMENTS: Stratifying films from SME solutions are formed and the heights of the steps are recorded. The viscosity of mixed SME + CAPB solutions is measured at various concentrations and weight ratios of the two surfactants.
FINDINGS: By theoretical analysis of the foam film data, we established that at 30-100 mM SME spherical micelles are formed and their aggregation number was determined. The addition of calcium ions, as in hard water, does not produce significant effect. However, SME and CAPB exhibit a strong synergism with respect to micelle growth as indicated by the high solution's viscosity. For this reason, the SME + CAPB mixtures represent a promising system for formulations in personal-care and house-hold detergency, having in mind also other useful properties of SME, such as high hard water tolerance, biodegradability and skin compatibility.
Comparison of Indo-Pacific humpback dolphin (Sousa chinensis) whistles from two areas of western Peninsular Malaysia

Hoffman JM, Ponnampalam LS, Araújo CC, Wang JY, Kuit SH, Hung SK

J Acoust Soc Am, 2015 Nov;138(5):2829-35.
PMID: 26627759 DOI: 10.1121/1.4934254

Differences in the acoustic variables of whistles emitted by Indo-Pacific humpback dolphins (Sousa chinensis) from two coastal locations along western Peninsular Malaysia were investigated. Duration, frequency, and frequency modulation variables were extracted from and used to characterize recordings of free-ranging humpback dolphins that were made using a broadband towed hydrophone. A total of 960 whistles from Matang Mangroves and 823 whistles from Langkawi Island were used in analyses. The whistles of Malaysian humpback dolphins covered frequencies from 1231 to 27 120 Hz with durations from 0.010-1.575 s. Significant multivariate differences were found in whistles emitted between locations. Significant differences were also found between dolphins of the two locations in their whistle duration, frequency modulation, and all frequency variables except for minimum frequency, which is likely under morphological constraints. The differences in whistles may be related to adaptations to the local acoustic habitat or unique whistles may have developed due to social interactions within each location, or broader scale differences resulting from geographic separation between the locations.
Surface active complexes formed between keratin polypeptides and ionic surfactants

Pan F, Lu Z, Tucker I, Hosking S, Petkov J, Lu JR

J Colloid Interface Sci, 2016 Dec 15;484:125-134.
PMID: 27599381 DOI: 10.1016/j.jcis.2016.08.082

Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.
Rheology of mixed solutions of sulfonated methyl esters and betaine in relation to the growth of giant micelles and shampoo applications

Yavrukova VI, Radulova GM, Danov KD, Kralchevsky PA, Xu H, Ung YW, et al.

Adv Colloid Interface Sci, 2020 Jan;275:102062.
PMID: 31718784 DOI: 10.1016/j.cis.2019.102062

This is a review article on the rheological properties of mixed solutions of sulfonated methyl esters (SME) and cocamidopropyl betaine (CAPB), which are related to the synergistic growth of giant micelles. Effects of additives, such as fatty alcohols, cocamide monoethanolamine (CMEA) and salt, which are expected to boost the growth of wormlike micelles, are studied. We report and systematize the most significant observed effects with an emphasis on the interpretation at molecular level and understanding the rheological behavior of these systems. The experiments show that the mixing of SME and CAPB produces a significant rise of viscosity, which is greater than in the mixed solutions of sodium dodecyl sulfate and CAPB. The addition of fatty alcohols, CMEA and cationic polymer, leads to broadening of the synergistic peak in viscosity without any pronounced effect on its height. The addition of NaCl leads to a typical salt curve with high maximum, but in the presence of dodecanol this maximum is much lower. At lower salt concentrations, the fatty alcohol acts as a thickener, whereas at higher salt concentrations - as a thinning agent. Depending on the shape of the frequency dependences of the measured storage and loss moduli, G' and G", the investigated micellar solutions behave as systems of standard or nonstandard rheological behavior. The systems with standard behavior obey the Maxwell viscoelastic model (at least) up to the crossover point (G' = G") and can be analyzed in terms of the Cates reptation-reaction model. The systems with nonstandard rheological behavior obey the Maxwell model only in a restricted domain below the crossover frequency; they can be analyzed in the framework of an augmented version of the Maxwell model. The methodology for data analysis and interpretation could be applied to any other viscoelastic micellar system.
Association of urbanicity with psychosis in low- and middle-income countries

DeVylder JE, Kelleher I, Lalane M, Oh H, Link BG, Koyanagi A

JAMA Psychiatry, 2018 Jul 01;75(7):678-686.
PMID: 29799917 DOI: 10.1001/jamapsychiatry.2018.0577

Importance: Urban residence is one of the most well-established risk factors for psychotic disorder, but most evidence comes from a small group of high-income countries.
Objective: To determine whether urban living is associated with greater odds for psychosis in low- and middle-income countries (LMICs).
Design, Setting, and Participants: This international population-based study used cross-sectional survey data collected as part of the World Health Organization (WHO) World Health Survey from May 2, 2002, through December 31, 2004. Participants included nationally representative general population probability samples of adults (≥18 years) residing in 42 LMICs (N = 215 682). Data were analyzed from November 20 through December 5, 2017.
Exposures: Urban vs nonurban residence, determined by the WHO based on national data.
Main Outcomes and Measures: Psychotic experiences, assessed using the WHO Composite International Diagnostic Interview psychosis screen, and self-reported lifetime history of a diagnosis of a psychotic disorder.
Results: Among the 215 682 participants (50.8% women and 49.2% men; mean [SD] age, 37.9 [15.7] years), urban residence was not associated with psychotic experiences (odds ratio [OR], 0.99; 95% CI, 0.89-1.11) or psychotic disorder (OR, 0.89; 95% CI, 0.76-1.06). Results of all pooled analyses and meta-analyses of within-country effects approached a null effect, with an overall OR of 0.97 (95% CI, 0.87-1.07), OR for low-income countries of 0.98 (95% CI, 0.82-1.15), and OR for middle-income countries of 0.96 (95% CI, 0.84-1.09) for psychotic experiences and an overall OR of 0.92 (95% CI, 0.73-1.16), OR for low-income countries of 0.92 (95% CI, 0.66-1.27), and OR for middle-income countries of 0.92 (95% CI, 0.67-1.27) for psychotic disorder.
Conclusions and Relevance: Our results provide evidence that urbanicity, a well-established risk factor for psychosis, may not be associated with elevated odds for psychosis in developing countries. This finding may provide better understanding of the mechanisms by which urban living may contribute to psychosis risk in high-income countries, because urban-rural patterns of cannabis use, racial discrimination, and socioeconomic disparities may vary between developing and developed nations.
Study name: World Health Survey (Malaysia is a study site)

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