Microfluidic quantum sensing platform for lab-on-a-chip applications.

Lab-on-a-chip (LOC) applications have emerged as invaluable physical and life sciences tools. The advantages stem from advanced system miniaturization, thus, requiring far less sample volume while allowing for complex functionality, increased reproducibility, and high throughput. However, LOC applications necessitate extensive sensor miniaturization to leverage these inherent advantages fully. Atom-sized quantum sensors are highly promising to bridge this gap and have enabled measurements of temperature, electric and magnetic fields on the nano- to microscale. Nevertheless, the technical complexity of both disciplines has so far impeded an uncompromising combination of LOC systems and quantum sensors. Here, we present a fully integrated microfluidic platform for solid-state spin quantum sensors, like the nitrogen-vacancy (NV) center in diamond. Our platform fulfills all technical requirements, such as fast spin manipulation, enabling full quantum sensing capabilities, biocompatibility, and easy adaptability to arbitrary channel and chip geometries. To illustrate the vast potential of quantum sensors in LOC systems, we demonstrate various NV center-based sensing modalities for chemical analysis in our microfluidic platform, ranging from paramagnetic ion detection to high-resolution microscale NV-NMR. Consequently, our work opens the door for novel chemical analysis capabilities within LOC devices with applications in electrochemistry, high-throughput reaction screening, bioanalytics, organ-on-a-chip, or single-cell studies.

How are family doctors serving the Hong Kong community during the COVID-19 outbreak? A survey of HKCFP members.

INTRODUCTION: This study evaluated the preparedness of family doctors during the early phase of the coronavirus disease 2019 (COVID-19) outbreak in Hong Kong. METHODS: All members of the Hong Kong College of Family Physicians were invited to participate in a cross-sectional online survey using a 20-item questionnaire to collect information on practice preparedness for the COVID-19 outbreak through an email followed by a reminder SMS message between 31 January 2020 and 3 February 2020. RESULTS: Of 1589 family doctors invited, 491 (31%) participated in the survey, including 242 (49%) from private sector. In all, 98% surveyed doctors continued to provide clinical services during the survey period, but reduced clinic service demands were observed in 45% private practices and 24% public clinics. Almost all wore masks during consultation and washed hands between or before patient contact. Significantly more private than public doctors (80% vs 26%, P<0.001) experienced difficulties in stocking personal protective equipment (PPE); more public doctors used guidelines to manage suspected patients. The main concern of the respondents was PPE shortage. Respondents appealed for effective public health interventions including border control, quarantine measures, designated clinic setup, and public education. CONCLUSION: Family doctors from public and private sectors demonstrated preparedness to serve the community from the early phase of the COVID-19 outbreak with heightened infection control measures and use of guidelines. However, there is a need for support from local health authorities to secure PPE supply and institute public health interventions.

Inverse relationship between hepatic steatosis and hepatitis B viremia: Results of a large case-control study.

The potential interaction between chronic hepatitis B (CHB) and nonalcoholic fatty liver disease (NAFLD), two of the most prevalent liver diseases worldwide, has not been well defined. We performed liver stiffness (LS) and controlled attenuation parameter (CAP) measurements using transient elastography in 1202 CHB patients. Of these, 601 steatotic patients were matched with nonsteatotic controls in a 1:1 ratio by age, gender, nucleoside analogue treatment status, and treatment duration. Severe fibrosis was defined according to EASL-ALEH criteria, and steatosis was defined as CAP ≥222 dB m-1 . Anthropometric measurements and metabolic-related parameters were recorded. The mean age of the 1202 patients (51.4% male) was 51.8 years. 696 patients (57.9%) were on nucleoside analogues for a median duration of 76.2 months. Among treatment-naïve patients, median serum HBV DNA was lower in steatotic individuals than in controls (3.0 vs 3.4 log IU mL-1 , P < .05), with this inverse relationship remaining significant in multivariate analysis (odds ratio 0.859, 95% CI 0.743-0.994, P < .05). With increased steatosis severity, there was a stepwise decrease in median HBV DNA levels (3.1 and 2.6 log IU mL-1 in no steatosis and severe steatosis, respectively, P = .032). Steatosis was associated with a higher median LS (5.4 kPa vs 5.0 kPa, P < .001). Severe steatosis, when compared to mild/moderate steatosis, was associated with an increased percentage of severe fibrosis (23.2% and 12.6%, respectively, P = .005). We conclude that severe steatosis was associated with increased fibrosis in CHB patients. Increasing steatosis was independently associated with lower serum HBV DNA levels, suggesting its potential negative effects on viral replication.

Randomised clinical trial: rifaximin versus placebo for the treatment of functional dyspepsia.

BACKGROUND: Gut dysbiosis may contribute to pain and bloating in patients with functional gastrointestinal disease. AIMS: To determine if treatment with rifaximin would improve the symptoms of functional dyspepsia in Chinese patients in a double-blinded, randomised, placebo-controlled trial. METHODS: Consecutive subjects with a diagnosis of functional dyspepsia as per the Rome III criteria were randomised to receive rifaximin 400 mg or placebo, all taken three times daily for 2 weeks. The investigators and study subjects were blinded to the treatment allocation. Subjects were followed up for 8 weeks. The primary end point was adequate relief of global dyspeptic symptoms (GDS). Secondary endpoints were relief of individual dyspeptic symptoms. RESULTS: Eighty-six subjects were recruited. At week 8, there were significantly more subjects in the rifaximin than in the placebo group who experienced adequate relief of GDS (78% vs. 52%, P = 0.02). A trend favouring rifaximin group was also noted in the preceding 4 weeks. Rifaximin was also superior to placebo in providing adequate relief of belching and post-prandial fullness/bloating (PPF) in subjects at week 4. Subgroup analysis revealed that female subjects had more significant response to rifaximin treatment (adequate relief of GDS at week 4: 76% vs. 42%, P = 0.006; week 8: 79% vs. 47%, P = 0.008), as well as improvements in their belching and PPF at week 4. The incidences of adverse effects were similar in both groups. CONCLUSIONS: Treatment with 2 weeks of rifaximin led to adequate relief of global dyspeptic symptoms, belching and post-prandial fullness/bloating in subjects with functional dyspepsia. The difference was more marked in females. (clinicaltrials.org NCT01643083).

Body-mass index is associated with fibrosis regression during long-term nucleoside analogue therapy in chronic hepatitis B.

BACKGROUND: Factors influencing changes in liver stiffness measurements during long-term nucleoside analogue therapy for chronic hepatitis B (CHB) have not been thoroughly investigated. AIM: To identify determinants of on-treatment fibrosis regression in CHB. METHODS: We performed follow-up liver stiffness and controlled attenuation parameter measurements on nucleoside analogue-treated CHB patients with severe liver fibrosis, according to EASL-ALEH criteria, diagnosed by transient elastography in 2006-2008. Anthropometric measurements and different metabolic parameters were recorded. RESULTS: Among 257 patients with severe liver fibrosis by initial transient elastography, 123 (47.9%) were recruited for reassessment. Median treatment duration was 87.5 (interquartile range 75.3-102.2) months; 97.5% had undetectable HBV DNA. There was a significant reduction in median liver stiffness from 14.6 to 8.3 kPa (P < 0.001). A total of 29.3% had fibrosis regression, with lower rates of 17.9%, 14.9% and 11.5% noted in patients with body-mass index (BMI) ≥25 kg/m2 , metabolic syndrome and diabetes, respectively. Absence of BMI ≥25 kg/m2 , diabetes and metabolic syndrome, when compared with presence of any one of these three factors, was associated with increased fibrosis regression (43.1% vs. 16.9%, P = 0.001). Multivariate analysis found a lower BMI to be the only factor independently associated with fibrosis regression (P = 0.034, odds ratio 0.68, 95% CI 0.48-0.97). No association was noted between controlled attenuation parameter measurements and fibrosis regression (P > 0.05). CONCLUSION: An increased BMI hindered fibrosis regression in patients with chronic hepatitis B during nucleoside analogue treatment, suggesting that control of metabolic risk factors, in addition to virologic suppression via antiviral therapy, might be needed to halt the fibrogenic process in chronic hepatitis B.

GlpC gene is responsible for biofilm formation and defense against phagocytes and imparts tolerance to pH and organic solvents in Proteus vulgaris.

Biofilm-forming bacteria are highly resistant to antibiotics, host immune defenses, and other external conditions. The formation of biofilms plays a key role in colonization and infection. To explore the mechanism of biofilm formation, mutant strains of Proteus vulgaris XC 2 were generated by Tn5 random transposon insertion. Only one biofilm defective bacterial species was identified from among 500 mutants. Inactivation of the glpC gene coding an anaerobic glycerol-3-phosphate dehydrogenase subunit C was identified by sequence analysis of the biofilm defective strain. Differences were detected in the growth phenotypes of the wild-type and mutant strains under pH, antibiotic, and organic solvent stress conditions. Furthermore, we observed an increase in the phagocytosis of the biofilm defective strain by the mouse macrophage RAW264.7 cell line compared to the wild-type strain. This study shows that the glpC gene plays an important role in biofilm formation, in addition to imparting pH, organic solvent, and antibiotic tolerance, and defense against phagocytosis to Proteus sp. The results further clarified the mechanism of biofilm formation at the genomic level, and indicated the importance of the glpC gene in this process. This data may provide innovative therapeutic measures against P. vulgaris infections; furthermore, as an important crocodile pathogen, this study also has important significance in the protection of Chinese alligators.

Screening miRNAs related to different subtypes of breast cancer with miRNAs microarray.

AIM: The aim of this study was to screen miRNAs related to different subtypes of breast cancer and their target genes to identify new markers of tumor subtype. MATERIALS AND METHODS: The miRNA expression profiles of breast cancer GSE38867 including 7 ductal carcinoma in situ breast (DCIS) cancer samples, 7 invasive breast cancer samples, 7 metastatic breast cancer samples, and 7 normal breast samples) were downloaded from Gene Expression Omnibus (GEO) database. Limma package in R software was applied to identify specific differentially expressed miRNAs of different subtypes of breast cancer. MicroRNA.org database source was used to predict the target genes of the identified differentially expressed miRNAs. We integrated the target genes and their interacted genes (predicted by STRING) into DAVID to perform the GO function and KEGG pathway analyses. RESULTS: Compared to the normal control, a total of 21, 47, and 107 differentially expressed miRNAs were screened in DCIS, invasive and metastatic breast cancer, respectively. Specific differentially expressed miRNAs of the three subtypes were identified, including hsa-miR-99a and hsa-miR-151-3p for DCIS breast cancer, hsa-miR-145 and hsa-miR-210 for invasive breast cancer, and has-miR-205 and has-miR-361-5p metastatic breast cancer. Furthermore, 220, 43, 446, 307, 587 and 328 interaction pairs of the specific miRNA targets were predicted. Multiple GO functions and KEGG pathways were enriched with the miRNA targets and their interacted genes. CONCLUSIONS: We screened the most representative miRNAs of the three different subtypes of breast cancer, which may act as the putative markers in the diagnosis of different subtypes of breast cancer.

Linearized hepatitis B surface antigen and hepatitis B core-related antigen in the natural history of chronic hepatitis B.

Changes in two novel HBV serological markers, linearized hepatitis B surface antigen (HQ-HBsAg) and hepatitis B core-related antigen (HBcrAg), in the natural history of chronic hepatitis B (CHB) have not been well characterized. Serum HQ-HBsAg and HBcrAg levels of 404 Asian treatment-naïve CHB patients were analysed in a cross-sectional manner. Patients were categorized into five groups: immune tolerant (IT group, n=52), immune clearance (IC group, n=105), hepatitis B e antigen (HBeAg)-negative hepatitis (ENH group, n=97), HBeAg-negative quiescent group (ENQ group, n=95) and CHB with hepatitis B surface antigen (HBsAg) seroclearance (SC group, n=55). HQ-HBsAg and HBcrAg were measured and correlated with HBV DNA, HBsAg, HBV genotype and clinical parameters. HQ-HBsAg showed good correlation with HBsAg, especially in the ENQ group (r=0.874, p<0.001). Correlation of HQ-HBsAg with HBV DNA was less prominent and weakest in the ENH group (r=0.268, p 0.008). HBcrAg correlated best with HBV DNA in the ENQ group (r=0.537, p<0.001). In the ENQ group, 42.1% of patients had undetectable HBcrAg; this subgroup of patients, when compared with those with detectable HBcrAg, had significantly lower median HBV DNA (3.17/4.48 log IU/mL, p<0.001) and HBsAg (5.05/5.96 log mIU/mL, p<0.001) levels. Forty per cent of the SC group patients had detectable HQ-HBsAg and/or HBcrAg up to 42 months after HBsAg seroclearance. When comparing anti-HBs positivity and median time after HBsAg seroclearance in the SC group with and without detectable HQ-HBsAg/HBcrAg, there was no significant difference (22.7% and 36.4%, respectively, p 0.284, and 76.5 and 93.2 months, respectively, p 0.245). HQ-HBsAg and HBcrAg showed unique patterns of distribution throughout the five disease phases of CHB, including high detectability rates after HBsAg seroclearance, opening up different possibilities for their applicability.

Correlation between Klebsiella pneumoniae carrying pLVPK-derived loci and abscess formation.

Klebsiella pneumoniae-caused liver abscess (KLA) is an emerging infectious disease. However, factors other than K1-specific loci that contribute to the pathogenesis of this disease have not been identified. pLVPK is a 219,385-bp plasmid of K. pneumoniae CG43, an invasive K2 strain associated with KLA. We aimed in this study to evaluate the involvement of pLVPK in K. pneumoniae virulence and its clinical significance in abscess formation. A pLVPK-cured CG43 was isolated and its virulence was examined in a mouse model. The prevalence of pLVPK-derived loci terW, iutA, rmpA, silS, and repA was investigated in 207 clinical isolates by screening with specific primers. Loss of pLVPK abolished the ability of K. pneumoniae to disseminate into extraintestinal sites and, consequently, attenuated abscess formation in mice. Primary K. pneumoniae abscess isolates (n = 94) were more likely to be terW (+)-iutA (+)-rmpA (+)-silS (+) than those related to non-abscess infections (n = 113) (62% vs. 27%; p < 0.0001). Logistic regression analysis indicated that the presence of the terW-rmpA-iutA-silS loci was a significant risk factor (odds ratio, 4.12; 95% confidence interval, 2.02-8.4; p < 0.0001) for abscess formation. pLVPK is a determinant for K. pneumoniae virulence and infection with strains carrying the pLVPK-derived terW-rmpA-iutA-silS loci may predispose patients to abscess formation.

Concentrations of functional lipids in abraded fractions of hulless barley and effect of storage.

Hulless barley kernels were sequentially abraded to achieve 4%, 8%, 16%, 24%, 32%, and 40% removal. Abraded fines, kernels, and ground kernels were stored at 35 degrees C and 75% relative humidity for 3 wk. Stored samples were extracted and the levels of oil, free phytosterols, tocopherols (Ts), and tocotrienols (T3s) were analyzed and compared with freshly abraded fractions. The results revealed that oil, sterols, and Ts were concentrated in the outer layers, particularly in the germ layer. In whole kernels, homologues of both Ts and T3s showed the same ranking order in concentrations as alpha > gamma > beta > delta. The homologue composition of Ts remained the same but that of T3s changed across the kernel. The %T3 in total tocols increased in fractions with increasing endosperm tissue. Storage caused no change in oil and Ts but significant changes in sterols and T3s. The changes were differential among T3 isomers, with alpha-T3 decreasing and delta-T3 increasing. The degradation of alpha-T3 was accelerated in fractions with more endosperm tissue. Grinding kernel samples before storage accelerated sterol degradation but had a limited effect on changes of T3s. A 2nd experiment using a different hulless barley line and ambient storage for 6 mo confirmed all the findings except that the changing trend for sterols was inconsistent. These results provide practical information to those who wish to produce a barley fraction enriched with a particular functional lipid and maintain stability of their products.

Concentrations of cat and dust-mite allergens in dust samples from 92 large US office buildings from the BASE Study.

UNLABELLED: The concentrations of cat (Fel d1) and dust-mite (Der f1 and Der p1) allergens were measured in 92 large office buildings in the US Environmental Protection Agency's Building Assessment Survey and Evaluation (BASE) Study (251 dust samples; one to four samples per building). Fel d1 was detected in almost all buildings and samples (91 buildings, 99%; 235 samples, 94%; range: <0.01-19 microg/g; median: 0.3 microg/g). Cat allergen exceeded 1 microg/g (a lower symptom threshold) in 56 samples (22%) from 45 buildings, but exceeded 8 microg/g (a sensitization threshold) in only two samples (1%) from two buildings. Der f1 or Der p1 was found in approximately half of all buildings and samples (63 and 70% of buildings; 45 and 51% of samples; range: <0.01-53 microg/g and <0.01-25 microg/g; median: <0.02 and 0.03 microg/g, respectively). Mite allergen exceeded 2 microg/g (a sensitization threshold) in seven samples (3%) from five buildings and exceeded 10 microg/g (a symptom threshold) in three samples (1%) from three buildings. Fel d1 concentration was significantly higher in samples collected in summer (June to September, 48 buildings), but cat allergen was not correlated with either mite allergen. Der f1, but not Der p1, concentration tended to be higher in samples collected in winter (December to April, 44 buildings), and the two mite allergens were significantly correlated only in winter. Cat and mite allergens were detected in 78% of representative US office buildings, but the concentrations seldom exceeded levels associated with sensitization or symptom provocation. PRACTICAL IMPLICATIONS: The information on the concentrations of cat and dust-mite allergens in representative large US offices has expanded the baseline data available for interpretation of measurements from other building investigations. With suggested refinements, the BASE protocol for measurement of allergen concentrations in dust samples may serve as a guide to future studies of building characteristics, bioaerosol concentrations, and occupant perceptions of the indoor environment.

Impact of severe respiratory syndrome on anxiety levels of front-line health care workers.

OBJECTIVE: To identify anxiety levels among front-line health care workers during the 2003 severe acute respiratory syndrome outbreak. DESIGN: Questionnaire survey. SETTING: Regional hospital, Hong Kong. PARTICIPANTS: All hospital staff were given a questionnaire; administrative staff who had not had any patient contact served as controls. MAIN OUTCOME MEASURES: Levels of contact with patients who had severe acute respiratory syndrome were measured and correlated with anxiety levels as determined by the State-Trait Anxiety Inventory. RESULTS: Of 4252 questionnaires distributed between May and June 2003, 2040 (48.0%) were returned and 1926 (45.3%) were valid for analysis. Overall, 534 (27.7%) respondents had had contact with patients with severe acute respiratory syndrome. Anxiety scores ranged from 20 to 80, and mean (standard deviation) scores were higher among staff who had had contact with patients with severe acute respiratory syndrome than among those who had not (52.6 [10.5] versus 49.8 [10.1], respectively; P<0.01). Mean anxiety levels were higher among workmen, health care assistants, and nurses than among administrative staff controls or doctors (P<0.01). Anxiety scores were correlated with burnout scores (Pearson's correlation coefficient, 0.52-0.59) and with discomfort from wearing protective gear (0.21-0.32). CONCLUSION: Severe acute respiratory syndrome has likely stressed the public health care system. Prediction and early identification of adverse factors in a crisis situation would allow early implementation of interventions to reduce and counteract the impact of this stress.

Antinociceptive effect of a novel long-acting nalbuphine preparation.

BACKGROUND: A long-acting analgesic may be particularly desirable in patients suffering from long-lasting pain. The aim of the study was to evaluate the antinociceptive effect of a novel nalbuphine preparation and to determine its duration of action. METHODS: The antinociceptive effects of i.m. nalbuphine HCl in saline and nalbuphine base in sesame oil were evaluated in rats. The in vitro drug-releasing profiles of nalbuphine HCl and base in different preparations were also evaluated. RESULTS: We found that i.m. nalbuphine HCl 25, 50 and 100 micromol kg(-1) produced dose-related antinociceptive effects with a duration of action of 1.5, 2 and 3 h, respectively. i.m. nalbuphine base 100, 200 and 400 micromol kg(-1) also produced dose-related antinociceptive effects but with longer durations of action: 27, 49 and 55 h, respectively. In vitro studies demonstrated that nalbuphine base in sesame oil had the slowest drug-releasing profile of the different preparations. CONCLUSIONS: i.m. injection of an oil formulation of nalbuphine base produced a long-lasting antinociceptive effect.

Physiognomy and teeth: an ethnographic study among young and middle-aged Hong Kong adults.

OBJECTIVES: To determine knowledge and beliefs about traditional physiognomy (judging an individual's character from their facial appearance) concerning teeth among young (17-26) and middle-aged (35-44) Hong Kong adults. METHODS: In a cross sectional ethnographical telephone survey, 400 adults were interviewed about 16 traditional physiognomy concerning teeth (in consultation with a Feng Shui specialist). RESULTS: Most completed the interview (93%, 373). Over half the study group (63%, 234) claimed they had heard of aspects of physiognomy concerning teeth, and a quarter (24%, 88) believed in such ideologies. Variations in knowledge and beliefs were apparent among people of different age (P < 0.01), gender (P < 0.05), educational attainment (P < 0.01), economic status (P < 0.01), place of birth (P < 0.01) and religion (P < 0.01). Their knowledge and belief in aspects of physiognomy concerning teeth was also associated with reported use of dental services (P < 0.01). CONCLUSION: Among young and middle-aged adults in Hong Kong, knowledge and beliefs concerning traditional physiognomy regarding teeth is strong, and socio-demographic variations exist in these perceptions. These findings have implications for all those involved in the delivery of dental care in multicultural societies and in raising cultural awareness about traditional health beliefs.

The zebrafish space cadet gene controls axonal pathfinding of neurons that modulate fast turning movements.

All vertebrates depend on neural circuits to produce propulsive movements; however, the contribution of individual neural cell types to control such movements are not well understood. We report that zebrafish space cadet mutant larvae fail to initiate fast turning movements properly, and we show that this motor phenotype correlates with axonal defects in a small population of commissural hindbrain neurons, which we identify as spiral fiber neurons. Moreover, we demonstrate that severing spiral fiber axons produces space cadet-like locomotor defects, thereby providing compelling evidence that the space cadet gene plays an essential role in integrating these neurons into the circuitry that modulates fast turning movements. Finally, we show that axonal defects are restricted to a small set of commissural trajectories, including retinal ganglion cell axons and spiral fiber axons, and that the space cadet gene functions in axonal pathfinding. Together, our results provide a rare example in vertebrates of an individual neuronal cell type that contributes to the expression of a defined motor behavior. Movies available on-line

A survey of environmental tobacco smoke controls in California office buildings.

A survey of environmental tobacco smoke (ETS) controls in California office buildings was carried out to obtain information of the type and distribution of ETS controls in office buildings and to evaluate the effectiveness of various ETS controls. A total of 118 smoking areas in 111 county and city buildings were inspected to collect information on the type of ETS controls. Only 31% of the smoking areas inspected were physically separated from nonsmoking areas with full floor-to-true-ceiling walls, 25% exhausted air to the outside, and 38% did not recirculate air to non-smoking areas. A total of 23 smoking areas and their adjacent non-smoking areas in 21 buildings were monitored for nicotine and fluorescent particulate matter (FPM). A tracer gas, sulfur hexafluoride (SF6), was released in smoking areas to measure the air leakage from smoking areas to adjacent non-smoking areas. The measurements of nicotine, FPM, and SF6 have shown large variations of the effectiveness of ETS controls. The least effective type of smoking area studied were open areas with no physical barriers between smoking and nonsmoking areas, no exhaust to the outside and no return air separation. On the contrary, smoking rooms with three ETS controls (i.e., physical separation, exhaust to outside, and no air recirculation) were the most effective design in containing ETS within smoking areas.

Multiple actinomyces brain abscesses: case report.

A case of multiple cerebral abscesses caused by actinomyces is reported in a 37 year old male with mucoepidermoid carcinoma of the right lung. In conjunction with penicillin, sulfonamide and erythromycin, the patient underwent stereotactic surgery for aspiration of the brain abscesses under (CT). The bacteria, considered to originate from the right lung, were identified from the abscess material obtained at surgery. Using proper therapy to control infection and intracranial pressure is important. A lon g term follow up with frequent computerised tomography evaluation has been conducted and the patient outcome has been successful recovery.

Unintentional carbon monoxide deaths in California from residential and other nonvehicular sources.

To investigate risk factors of unintentional carbon monoxide deaths in California from nonvehicular sources, we identified 270 deaths resulting from nonvehicular sources of carbon monoxide poisoning from death certificates and coroners' investigation reports. Data recorded between 1979 and 1988 in the state of California on risk factors and carbon monoxide sources were abstracted from investigation reports. We also used census and state statistics to calculate rates and relative risks. The highest rates, which occurred in winter, were found among males, African Americans, and the elderly. Relative risks (in parentheses) were higher among individuals who (a) lived in multiunit dwellings (2.1), (b) dwelled in mobile/trailer homes (4.7), and (c) resided in temporary shelters (30.0) than among individuals who lived in single-family houses (1.0). Unvented combustion heating appliances and charcoal fuel were associated significantly with the risks of fatal unintentional carbon monoxide poisoning.