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Nguyen HL, Gropp C, Yaghi OM. Reticulating 1D Ribbons into 2D Covalent Organic Frameworks by Imine and Imide Linkages. J Am Chem Soc 2020; 142:2771-2776. [DOI: 10.1021/jacs.9b13971] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Nguyen HL, Hanikel N, Lyle SJ, Zhu C, Proserpio DM, Yaghi OM. A Porous Covalent Organic Framework with Voided Square Grid Topology for Atmospheric Water Harvesting. J Am Chem Soc 2020; 142:2218-2221. [DOI: 10.1021/jacs.9b13094] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Helal A, Nguyen HL, Al-Ahmed A, Cordova KE, Yamani ZH. An Ultrasensitive and Selective Metal–Organic Framework Chemosensor for Palladium Detection in Water. Inorg Chem 2019; 58:1738-1741. [DOI: 10.1021/acs.inorgchem.8b02871] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Al-Omari AA, Yamani ZH, Nguyen HL. Electrocatalytic CO₂ Reduction: From Homogeneous Catalysts to Heterogeneous-Based Reticular Chemistry. Molecules 2018; 23:E2835. [PMID: 30388731 PMCID: PMC6278299 DOI: 10.3390/molecules23112835] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/20/2018] [Accepted: 10/22/2018] [Indexed: 11/17/2022] Open
Abstract
CO₂, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO₂ could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH₃OH, or CH₄. To reduce CO₂, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed, the electroreduction method has received much consideration lately due to the simple operation, as well as environmentally friendly procedures that need to be optimized by both of the catalysts and the electrochemical process. In the past few decades, we have witnessed an explosion in development in materials science-especially in regards to the porous crystalline materials based on the strong covalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs), as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters (Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density that belong to these tailorable structures, MOFs and COFs can be applied to many practical applications, such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications, which have been abundantly studied since the 1990s, CO₂ reduction catalyzed by reticular and extended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-art application. In this perspective, we highlight the achievement of homogeneous catalysts used for CO₂ electrochemical conversion and contrast it with the advances in new porous catalyst-based reticular chemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistry in the heterogeneous-catalyzed reduction of CO₂.
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Tu TN, Nguyen MV, Nguyen HL, Yuliarto B, Cordova KE, Demir S. Designing bipyridine-functionalized zirconium metal–organic frameworks as a platform for clean energy and other emerging applications. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.03.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
The chemistry of Ti-based MOFs, including their synthetic methods, crystal structures, topological evaluation, and promising applications, is precisely summarized and discussed.
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Nguyen LHT, Nguyen TT, Nguyen HL, Doan TLH, Tran PH. A new superacid hafnium-based metal–organic framework as a highly active heterogeneous catalyst for the synthesis of benzoxazoles under solvent-free conditions. Catal Sci Technol 2017. [DOI: 10.1039/c7cy01668a] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new superacid Hf-based MOF, termed VNU-11-P-SO4, was used as an efficient heterogeneous catalyst for solvent-free 2-arylbenzoxazole synthesis.
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Tran TV, Le HTN, Ha HQ, Duong XNT, Nguyen LHT, Doan TLH, Nguyen HL, Truong T. A five coordination Cu(ii) cluster-based MOF and its application in the synthesis of pharmaceuticals via sp3 C–H/N–H oxidative coupling. Catal Sci Technol 2017. [DOI: 10.1039/c7cy00882a] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Five coordination sites of Cu(ii) cluster were found in VNU-18 that showed highly efficient catalytic property for the oxidative C–H activation via N–H bonds.
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Nguyen HL, Vu TT, Le D, Doan TLH, Nguyen VQ, Phan NTS. A Titanium–Organic Framework: Engineering of the Band-Gap Energy for Photocatalytic Property Enhancement. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02642] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Trinh QM, Nguyen HL, Do TN, Nguyen VN, Nguyen BH, Nguyen TVA, Sintchenko V, Marais BJ. Tuberculosis and HIV co-infection in Vietnam. Int J Infect Dis 2016; 46:56-60. [PMID: 27044521 DOI: 10.1016/j.ijid.2016.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022] Open
Abstract
UNLABELLED Tuberculosis (TB) and human immunodeficiency virus (HIV) infection are leading causes of disease and death in Vietnam, but TB/HIV disease trends and the profile of co-infected patients are poorly described. METHODS We examined national TB and HIV notification data to provide a geographic overview and describe relevant disease trends within Vietnam. We also compared the demographic and clinical profiles of TB patients with and without HIV infection. RESULTS During the past 10 years (2005-2014) cumulative HIV case numbers and deaths increased to 298,151 and 71,332 respectively, but access to antiretroviral therapy (ART) improved and new infections and deaths declined. From 2011-2014 routine HIV testing of TB patients increased from 58.9% to 72.5% and of all TB patients diagnosed with HIV in 2014, 2,803 (72.4%) received ART. The number of multidrug resistant (MDR)-TB cases enrolled for treatment increased almost 3-fold (578 to 1,532) from 2011-2014. The rate of HIV co-infection in MDR and non-MDR TB cases (51/1,532; 3.3% vs 3,774/100,555; 3.8%; OR 0.77, 95% CI 0.7-1.2) was similar in 2014. CONCLUSIONS The care of TB/HIV co-infected patients have shown sustained improvement in Vietnam. Rising numbers of MDR-TB cases is a concern, but this is not "driven" by HIV co-infection.
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Nguyen HL, Gándara F, Furukawa H, Doan TLH, Cordova KE, Yaghi OM. A Titanium-Organic Framework as an Exemplar of Combining the Chemistry of Metal- and Covalent-Organic Frameworks. J Am Chem Soc 2016; 138:4330-3. [PMID: 26998612 DOI: 10.1021/jacs.6b01233] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A crystalline material with a two-dimensional structure, termed metal-organic framework-901 (MOF-901), was prepared using a strategy that combines the chemistry of MOFs and covalent-organic frameworks (COFs). This strategy involves in situ generation of an amine-functionalized titanium oxo cluster, Ti6O6(OCH3)6(AB)6 (AB = 4-aminobenzoate), which was linked with benzene-1,4-dialdehyde using imine condensation reactions, typical of COFs. The crystal structure of MOF-901 is composed of hexagonal porous layers that are likely stacked in staggered conformation (hxl topology). This MOF represents the first example of combining metal cluster chemistry with dynamic organic covalent bond formation to give a new crystalline, extended framework of titanium metal, which is rarely used in MOFs. The incorporation of Ti(IV) units made MOF-901 useful in the photocatalyzed polymerization of methyl methacrylate (MMA). The resulting polyMMA product was obtained with a high-number-average molar mass (26 850 g mol(-1)) and low polydispersity index (1.6), which in many respects are better than those achieved by the commercially available photocatalyst (P-25 TiO2). Additionally, the catalyst can be isolated, reused, and recycled with no loss in performance.
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Nguyen HL, Nghia N, Lewis H. Quality Practices of Anatomic Pathology Labs in Vietnam. ACTA ACUST UNITED AC 2016. [DOI: 10.1093/crival/vaw006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Trinh QM, Nguyen HL, Nguyen VN, Nguyen TVA, Sintchenko V, Marais BJ. Tuberculosis and HIV co-infection-focus on the Asia-Pacific region. Int J Infect Dis 2016; 32:170-8. [PMID: 25809776 DOI: 10.1016/j.ijid.2014.11.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/24/2014] [Indexed: 12/23/2022] Open
Abstract
Tuberculosis (TB) is the leading opportunistic disease and cause of death in patients with HIV infection. In 2013 there were 1.1 million new TB/HIV co-infected cases globally, accounting for 12% of incident TB cases and 360,000 deaths. The Asia-Pacific region, which contributes more than a half of all TB cases worldwide, traditionally reports low TB/HIV co-infection rates. However, routine testing of TB patients for HIV infection is not universally implemented and the estimated prevalence of HIV in new TB cases increased to 6.3% in 2013. Although HIV infection rates have not seen the rapid rise observed in Sub-Saharan Africa, indications are that rates are increasing among specific high-risk groups. This paper reviews the risks of TB exposure and progression to disease, including the risk of TB recurrence, in this vulnerable population. There is urgency to scale up interventions such as intensified TB case-finding, isoniazid preventive therapy, and TB infection control, as well as HIV testing and improved access to antiretroviral treatment. Increased awareness and concerted action is required to reduce TB/HIV co-infection rates in the Asia-Pacific region and to improve the outcomes of people living with HIV.
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Doan TLH, Nguyen HL, Pham HQ, Pham-Tran NN, Le TN, Cordova KE. Tailoring the Optical Absorption of Water-Stable ZrIV- and HfIV-Based Metal-Organic Framework Photocatalysts. Chem Asian J 2015; 10:2660-8. [DOI: 10.1002/asia.201500641] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 07/31/2015] [Indexed: 11/11/2022]
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Hoang LTM, Ngo LH, Nguyen HL, Nguyen HTH, Nguyen CK, Nguyen BT, Ton QT, Nguyen HKD, Cordova KE, Truong T. An azobenzene-containing metal–organic framework as an efficient heterogeneous catalyst for direct amidation of benzoic acids: synthesis of bioactive compounds. Chem Commun (Camb) 2015; 51:17132-5. [DOI: 10.1039/c5cc05985b] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
An Zr-MOFs was demonstrated to be an efficient heterogeneous catalyst for direct amidation.
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Mendola A, Schlögel MJ, Ghalamkarpour A, Irrthum A, Nguyen HL, Fastré E, Bygum A, van der Vleuten C, Fagerberg C, Baselga E, Quere I, Mulliken JB, Boon LM, Brouillard P, Vikkula M. Mutations in the VEGFR3 signaling pathway explain 36% of familial lymphedema. Mol Syndromol 2013; 4:257-66. [PMID: 24167460 DOI: 10.1159/000354097] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2013] [Indexed: 12/13/2022] Open
Abstract
Lymphedema is caused by dysfunction of lymphatic vessels, leading to disabling swelling that occurs mostly on the extremities. Lymphedema can be either primary (congenital) or secondary (acquired). Familial primary lymphedema commonly segregates in an autosomal dominant or recessive manner. It can also occur in combination with other clinical features. Nine mutated genes have been identified in different isolated or syndromic forms of lymphedema. However, the prevalence of primary lymphedema that can be explained by these genetic alterations is unknown. In this study, we investigated 7 of these putative genes. We screened 78 index patients from families with inherited lymphedema for mutations in FLT4, GJC2, FOXC2, SOX18, GATA2, CCBE1, and PTPN14. Altogether, we discovered 28 mutations explaining 36% of the cases. Additionally, 149 patients with sporadic primary lymphedema were screened for FLT4, FOXC2, SOX18, CCBE1, and PTPN14. Twelve mutations were found that explain 8% of the cases. Still unidentified is the genetic cause of primary lymphedema in 64% of patients with a family history and 92% of sporadic cases. Identification of those genes is important for understanding of etiopathogenesis, stratification of treatments and generation of disease models. Interestingly, most of the proteins that are encoded by the genes mutated in primary lymphedema seem to act in a single functional pathway involving VEGFR3 signaling. This underscores the important role this pathway plays in lymphatic development and function and suggests that the unknown genes also have a role.
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Nguyen HL, Charpentier C, Nguyen N, de Truchis P, Molina JM, Ruxrungtham K, Delaugerre C. Longitudinal analysis of integrase N155H variants in heavily treated patients failing raltegravir-based regimens. HIV Med 2012; 14:85-91. [PMID: 22994529 DOI: 10.1111/j.1468-1293.2012.01039.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping. METHODS Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype. RESULTS No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA. CONCLUSIONS The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.
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Taylor WR, Nguyen K, Nguyen D, Nguyen H, Horby P, Nguyen HL, Lien T, Tran G, Tran N, Nguyen HM, Nguyen T, Nguyen HH, Nguyen T, Tran G, Farrar J, de Jong M, Schultsz C, Tran H, Nguyen D, Vu B, Le H, Dao T, Nguyen T, Wertheim H. The spectrum of central nervous system infections in an adult referral hospital in Hanoi, Vietnam. PLoS One 2012; 7:e42099. [PMID: 22952590 PMCID: PMC3431395 DOI: 10.1371/journal.pone.0042099] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 07/02/2012] [Indexed: 11/19/2022] Open
Abstract
Objectives To determine prospectively the causative pathogens of central nervous system (CNS) infections in patients admitted to a tertiary referral hospital in Hanoi, Vietnam. Methods From May 2007 to December 2008, cerebrospinal fluid (CSF) samples from 352 adults with suspected meningitis or encephalitis underwent routine testing, staining (Gram, Ziehl-Nielsen, India ink), bacterial culture and polymerase chain reaction targeting Neisseria meningitidis, Streptococcus pneumoniae, S. suis, Haemophilus influenzae type b, Herpes simplex virus (HSV), Varicella Zoster virus (VZV), enterovirus, and 16S ribosomal RNA. Blood cultures and clinically indicated radiology were also performed. Patients were classified as having confirmed or suspected bacterial (BM), tuberculous (TBM), cryptococcal (CRM), eosinophilic (EOM) meningitis, aseptic encephalitis/meningitis (AEM), neurocysticercosis and others. Results 352 (male: 66%) patients were recruited: median age 34 years (range 13–85). 95/352 (27.3%) diagnoses were laboratory confirmed and one by cranial radiology: BM (n = 62), TBM (n = 9), AEM (n = 19), CRM (n = 5), and neurocysticercosis (n = 1, cranial radiology). S. suis predominated as the cause of BM [48/62 (77.4%)]; Listeria monocytogenese (n = 1), S. pasteurianus (n = 1) and N. meningitidis (n = 2) were infrequent. AEM viruses were: HSV (n = 12), VZV (n = 5) and enterovirus (n = 2). 5 patients had EOM. Of 262/352 (74.4%) patients with full clinical data, 209 (79.8%) were hospital referrals and 186 (71%) had been on antimicrobials. 21 (8%) patients died: TBM (15.2%), AEM (10%), and BM (2.8%). Conclusions Most infections lacked microbiological confirmation. S. suis was the most common cause of BM in this setting. Improved diagnostics are needed for meningoencephalitic syndromes to inform treatment and prevention strategies.
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Nguyen HL, Leermakers M, Kurunczi S, Bozo L, Baeyens W. Mercury distribution and speciation in Lake Balaton, Hungary. THE SCIENCE OF THE TOTAL ENVIRONMENT 2005; 340:231-246. [PMID: 15752504 DOI: 10.1016/j.scitotenv.2004.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Revised: 08/19/2004] [Accepted: 08/19/2004] [Indexed: 05/24/2023]
Abstract
The distribution and speciation of mercury in air, rain, lake water, sediment, and zooplankton in Lake Balaton (Hungary) were investigated between 1999 and 2002. In air, total gaseous mercury (TGM) ranged from 0.4 to 5.9 ng m(-3) and particulate phase mercury (PPM) from 0.01 to 0.39 ng m(-3). Higher concentrations of both TGM and PPM occurred during daytime. Higher concentrations of PPM occurred in winter. In rain and snow, total mercury ranged from 10.8 to 36.7 ng L(-1) in summer but levels up to 191 ng L(-1) in winter. Monomethylmercury (MMHg) concentrations ranged from 0.09 to 1.26 ng L(-1) and showed no seasonal variations. Total Hg in the unfiltered lake water varied spatially, with concentrations ranging from 1.4 to 6.5 ng L(-1). Approximately 70% of the total Hg is dissolved. MMHg levels ranged from 0.08 to 0.44 ng L(-1) as total and from 0.05 to 0.37 ng L(-1) in the dissolved form. Lower Hg concentrations in the water column occurred in winter. In suspended particulate matter and in sediment, total mercury ranged from 9 to 160 ng g(-1) dw, and MMHg ranged from 0.07 to 0.84 ng g(-1) dw. In zooplankton, an average mercury level of 31.0+/-6.8 ng g(-1) dw occurred, with MMHg accounting for approximately 17%. In sediments, suspended-matter- and zooplankton-high Hg and MMHg levels occurred at the mouth of the River Zala, but, in the lake, higher concentrations occurred on the Northern side, and an increasing trend from north-west to north-east was observed. In general, regarding Hg, Lake Balaton can be considered as a relatively uncontaminated site. The high-pH and well-oxygenated water as well as the low organic matter content of the sediment does not favour the methylation of Hg. In addition, bioconcentration and bioaccumulation factors are relatively low compared to other aquatic systems.
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Nguyen HL, Leermakers M, Osán J, Török S, Baeyens W. Heavy metals in Lake Balaton: water column, suspended matter, sediment and biota. THE SCIENCE OF THE TOTAL ENVIRONMENT 2005; 340:213-30. [PMID: 15752503 DOI: 10.1016/j.scitotenv.2004.07.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Revised: 01/05/2004] [Accepted: 07/26/2004] [Indexed: 05/14/2023]
Abstract
During the period 1999-2002, five sampling cruises have been carried out on Lake Balaton to assess trace metal distribution in the lake and to identify major sources. Eighteen elements, including Cr, Co, Ni, Cu, Zn, Cd, Pb (trace metals) and Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr (major metals), were determined in one or more of the lake's compartments. Lower trace metal concentrations in rainwater were observed in June and February 2000, while much higher levels were present in September 2001 (during a storm event) and in snow (February 2000). In the Northern and Western parts of the lake, especially at the inflow of river Zala and the locations of the yacht harbours, metal concentrations were higher in almost all compartments. Because the lake is very shallow, storm conditions also change significantly the metal distributions in the dissolved and particulate phases. The Kis-Balaton protection system located on Zala river functions very efficiently for retaining suspended particulate matter (SPM; 72% retention) and associated metals. Metal concentrations in surface sediments of the lake showed a high variability. After normalisation for the fine sediment fraction, only a few stations including Zala mouth appeared to be enriched in trace metals. In zooplankton, Zn seemed to be much more elevated compared to the other trace metals. Based on the molar ratios of the trace metals in the various compartments and input flows of the lake, several trends could be deduced. For example, molar ratios of the trace metals in the dissolved and solid (suspended particulate matter and sediments) phases in the lake are fairly similar to those in Zala River.
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Hoang TQ, Nguyen HL, Tran NT, Homasson JP. [Evaluation of different fibroscopic sampling techniques for the diagnosis of isolated peripheral pulmonary nodules. A prospective study of 74 cases in Vietnam]. REVUE DE PNEUMOLOGIE CLINIQUE 2004; 60:265-268. [PMID: 15687909 DOI: 10.1016/s0761-8417(04)72111-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Isolated pulmonary nodules raise serious diagnostic problems. Combined imaging and endoscopic methods can often avoid exploratory thoracotomy. The situation is different however in developing countries where health facilities and technical availability are quite variable. Bronchial fibroscopy without image guidance can provide the diagnosis is an acceptable number of cases. We conducted a prospective study in 74 patients. After chest x-ray and CT scan of the lesion of interest, bronchial lavage was performed in each patient with brushings samples in 71 and transbronchial biopsy in 68. Riu staining was performed immediately in the endoscopy suite, providing an almost immediate diagnostic approach. The combination of lavage, brushing and biopsy provided a diagnostic yield as good as the brushings and biopsy combination. These endoscopic techniques gave the diagnosis of the specific lesion in 52 cases (70%). Most involved cancer but there were 15 cases of tuberculosis diagnosis, which remains frequent in developing countries.
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Leermakers M, Nguyen HL, Kurunczi S, Vanneste B, Galletti S, Baeyens W. Determination of methylmercury in environmental samples using static headspace gas chromatography and atomic fluorescence detection after aqueous phase ethylation. Anal Bioanal Chem 2003; 377:327-33. [PMID: 12898107 DOI: 10.1007/s00216-003-2116-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2003] [Revised: 05/30/2003] [Accepted: 06/12/2003] [Indexed: 11/29/2022]
Abstract
A rapid and automated method for the determination of monomethylmercury (MMHg) in environmental samples was developed using headspace gas chromatography with atomic fluorescence detection in combination with aqueous phase ethylation. Sample preparation steps were optimized for sediments, biological samples, and water samples using certified reference materials and real samples with a broad range of MMHg concentrations. Different extraction procedures were compared for both sediments and biological samples. The methods were applied in the intercomparison exercises for the certification of MMHg in sediments (IAEA 405) and in Oyster tissue (BCR 710) and the results were accepted for certification. The detection limits for MMHg are 0.002 ng Hg/g for sediments and biological samples and 0.01 ng Hg/L for water samples. The method was tested for methylation artifacts; no artifact was observed in the sediment samples and CRMs tested.
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Marrett LD, Nguyen HL, Armstrong BK. Trends in the incidence of cutaneous malignant melanoma in New South Wales, 1983-1996. Int J Cancer 2001; 92:457-62. [PMID: 11291086 DOI: 10.1002/ijc.1203] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The incidence of cutaneous malignant melanoma (CMM) has been rising in fair-skinned populations throughout the world for decades. The upward trend may, however, finally be slowing in some of these populations. Recent (1983-1996) CMM incidence trends for a high incidence area (New South Wales, Australia) have been examined according to gender, age group, body site and tumour thickness. Despite continuing upward trends in older age groups, particularly among men (e.g., 7.20% increase per year in men aged 75+), incidence for younger ages is stabilizing (in men) or declining (in women): average annual percentage changes of -3.03 and -0.88 were observed for women aged 15-34 and 35-54, respectively. Patterns suggest a birth-cohort effect, with those born since 1945 or 1950 having lower (females) or similar (males) rates to those born earlier. For each gender, all-ages incidence rose by a similar amount for each of the main body sites except the leg in women, where incidence fell by 0.49% per year. In men, the incidence of both thin (</=75 mm) and thick (>75 mm) melanomas increased (significantly, by 2.63% per year and non-significantly, by 0.93% per year, respectively) between 1989 and 1996. In women, incidence remained stable for both thickness subgroups. These data are consistent with a stabilization or reduction in either total sun exposure or intermittency of exposure among New South Wales cohorts born since about 1950. Because incidence rates are still much higher than they were a few decades ago, however, efforts to reduce sun exposure, particularly in children and youth, must continue.
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Nguyen HL, Gruber D, Bulinski JC. Microtubule-associated protein 4 (MAP4) regulates assembly, protomer-polymer partitioning and synthesis of tubulin in cultured cells. J Cell Sci 1999; 112 ( Pt 12):1813-24. [PMID: 10341201 DOI: 10.1242/jcs.112.12.1813] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We depleted MAP4, a ubiquitously expressed microtubule (MT)-associated protein previously shown to be capable of stabilizing MTs, from HeLa cells by stably expressing antisense RNA. These HeLa-AS cells, in which the MAP4 level was decreased to 33% of the wild-type level, displayed decreased content of total tubulin (65% of the wild-type level). The partitioning of cellular tubulin into protomer and polymer was altered in HeLa-AS cells: polymeric tubulin was decreased to 46% of the level in control cells, while protomeric tubulin was increased to 226% of the level in control cells. Tubulin protein synthesis was decreased, consistent with the tubulin autoregulation model, which proposes that tubulin protomer inhibits its own synthesis. Following release from drug-induced depolymerization, MTs in HeLa-AS cells reformed more slowly, and showed an increased focus on the centrosome, as compared to control cells. HeLa-AS cells also appeared to be less bipolar in shape and flatter than control cells. Our data suggest that MAP4 regulates assembly level of MTs and, perhaps through this mechanism, is involved in controlling spreading and shape of cells.
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Nguyen HL, Gruber D, McGraw T, Sheetz MP, Bulinski JC. Stabilization and functional modulation of microtubules by microtubule-associated protein 4. THE BIOLOGICAL BULLETIN 1998; 194:354-357. [PMID: 9664661 DOI: 10.2307/1543111] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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