Objective: To compare diary-reported trips and Global Positioning System (GPS) recording trips and identify the reasons for the discrepancies between two methods. Methods: The survey was conducted in Jiangning district in Nanjing city during July to September and November to December, 2015. Both the diary records and GPS method were used to investigate the travel behavior of 33 retired adults for 5 consecutive days. The GPS traces were display in Google Earth and then split into trips to compare with the diary records according to time and location. χ² test was used to analyze the influence of trip characteristics on misreporting rates of each method. Results: A total of 1 087 trips in the survey can be compared between the diary (n=909) and the GPS method (n=912). 7.3% (79/1 087) of the trips were only recorded by GPS method, and 11.8% (128/1 087) were only reported in the diary. Of the remaining 880 trips recorded by the both methods, 86.7% (763/880) matched each other, while 13.3% (117/880) did not. For the matched trips, the difference between the trip durations recorded by diary and GPS method was 2.0 (quartile was 6.0) minutes and the diary method overestimated about 25.0% trip durations when compared with the GPS method. The accuracy rates were 84.8%(903/1 065) and 86.9%(925/1 065) for diary and GPS method, respectively. Both methods were more likely to misreport the trip under 5 minutes. The misreporting rates of diary method for trips under 5 minutes were 6.8 times higher than trips over 30 minutes (21.7% vs 3.2%). The reporting accuracy was also significantly different among trips by different travel mode (P<0.05) for both methods, diary method had the lowest accuracy in reporting vehicles recorders (69.3%, 133/192), while GPS method was more accuracy in both biking (91.9%, 136/148) and vehicles recorders(89.6%, 172/192). The main reasons for misreporting by diary method were forgetting or unwilling to record and failing to record trips according to travel mode, while forgetting to carry GPS device, bad GPS signal and failing to locate the position were the main reasons for misreporting by GPS method. Conclusion The majority of the trips reported in diary and GPS method are well consistent with each other. Both of the methods should be used simultaneously in the survey of time-activity pattern to improve the data quality.

Objective: To analyze the clinical characteristics of community-acquired pneumonia (CAP) in children under five years of age and analyze the safety and efficiency of nasal continuous positive airway pressure (NCPAP) ventilation for CAP in this population. Method: This was a prospective multicenter study. Children who were admitted to these six centers with CAP and met the NCPAP ventilation indications, aged from 29 d to 5 years, were continuously included during November 2013 to October 2015. The baseline data were collected and NCPAP ventilation were then followed up by operation standards, and the vital signs and arterial blood gas change at special time points were observed and recorded. Any side effect associated with NCPAP were recorded. For categorical variables, comparisons were performed using Fisher test. Rank-sum test and t test were performed respectively for abnormal and normal distribution continuous variables. The variables pre-NCPAP and post-NCPAP were analyzed by repeated measures ANOVA analysis. Result: Totally 145 children were included, and 13 children were excluded due to incomplete data. One hundred and two children(77.3%)were ≤12 months; 91 children (68.9%) were from rural area. NCPAP ventilation was effective in 123 children, with a response rate of 93.2%, were all discharged with a better condition; it was ineffective in 9 children(6.8%), and they were all intubated and went on mechanical ventilation, 5 were discharged with a better condition, and 4 died after gaving up treatment. The gender, age, body weight, residence, main symptoms, main signs, imaging diagnosis, medications, partial pressure of oxygen(PaO₂), breath and heart rate before NCPAP treatment of two groups had no significant differences(allP>0.05). The rates of combining underlying diseases, trouble with feeding and cyanosis, and the partial pressure of carbon dioxide(PaCO₂ ) before NCPAP ventilation were higher in NCPAP ineffective group ((59±11 )vs.( 49±11) mmHg, 1 mmHg=0.133 kPa, t=-2.597, P=0.028); while the PaO₂/fraction of inspiration O₂ (FiO₂ ) before NCPAP was lower((150±37) vs. (207±63) mmHg, t=2.697, P=0.008). The breathing, heart rate and PaCO₂ of NCPAP effective group decreased significantly, while the PaO₂ and PaO₂/FiO₂ increased significantly after 2, 8, 24 h of NCPAP ventilation(all P=0.000). PaCO₂ in children with hypercapnia before NCPAP ventilation in NCPAP effective group decreased significantly ((48±9), (47±12), (45±11)vs.(58±7)mmHg, all P=0.000). All children tolerated well to NCPAP ventilation, and there were no severe side effects or complications associated with NCPAP ventilation. Conclusion NCPAP ventilation is safe and effectively improved the oxygenation and hypercapnia in infants with CAP. But it may not work well in children with underlying diseases, manifest as difficulty in feeding/cyanosis and extremely high PaCO₂ or low PaO₂/FiO₂, and they may need early intubation.

BACKGROUNDOptimal mineral intakes are important for infant growth and development. However, data on mineral compositions of breast milk in Chinese women are scarce, and most were acquired before 1990. The objectives of this study were three-fold: (1) to investigate the mineral compositions of Chinese healthy mothers' breast milk in different lactation stages; (2) to explore correlations among mineral concentrations in breast milk; and (3) to explore the associated factors affecting mineral compositions in breast milk.

METHODSThe inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze mineral concentrations in breast-milk of 444 healthy lactating women from three cities in China. A questionnaire was used to survey socio-demographic characteristics and pregnancy history. Food intakes by lactating women were measured using both food frequency questionnaire and one cycle of 24-hour dietary recall.

RESULTSMineral compositions of breast milk varied in different regions. Concentrations of most minerals were higher in the first one or two months of lactation, and then decreased with time, except for magnesium and iron. Inter-mineral correlations existed among several minerals. The calcium-to-phosphorus ratio was above 2:1 in each lactation stage. Women with caesarean section had higher concentration of iodine in the transitional milk (349.9 µg/kg) compared to women with natural delivery (237.5 µg/kg, P < 0.001). Dietary mineral intakes, supplements, food intake frequencies in the recent 6 months, maternal age and maternal BMI did not show significant correlations with concentrations of milk minerals (all P > 0.05).

CONCLUSIONSMilk minerals decreased with time, and changed most rapidly in the first one or two months of lactation. Caesarean section might affect the iodine level in transitional milk.

Adult ; Calcium ; administration & dosage ; metabolism ; Dietary Supplements ; Female ; Humans ; Iodine ; administration & dosage ; metabolism ; Lactation ; metabolism ; Mass Spectrometry ; Milk, Human ; chemistry ; metabolism ; Minerals ; administration & dosage ; analysis ; Phosphorus ; administration & dosage ; metabolism ; Pregnancy

BACKGROUNDInfancy is a critical period of growth and physiological development, in which breast milk is the best source of nutrients. Compared to western countries, research on breast milk of Chinese population are limited. Thus, it is necessary to measure breast milk energy and macronutrient concentrations of healthy urban Chinese mothers at different lactation stages, to expand the database of milk composition of Chinese population, and to examine whether dietary or other maternal factors can affect the levels of macronutrients in breast milk.

METHODSBreast milk of full expression of one side breast from 436 urban Chinese lactating mothers at 5-11 days, 12-30 days, 31-60 days, 61-120 days, and 121-240 days postpartum was obtained at 9:00 a.m. to 11:00 a.m. Total energy, lactose, protein, and fat contents were measured. 24-hour dietary recall was surveyed, and maternal nutrient intakes were analyzed.

RESULTSMilk composition changed over the course of lactation and large individual variations were documented. The concentrations were 61.3 kcal/dl for total energy, 7.1 g/dl for lactose, 0.9 g/dl for protein, and 3.4 g/dl for fat in mature milk. Stage of lactation was a strong factor affecting milk composition. Minimal evidence was found for associations between maternal current dietary intake and milk macronutrient concentration, consistently with prior research. Maternal body mass index (BMI) was positively associated with milk fat content, to a greater extent than did dietary intake. All other maternal characteristics were not significant for milk composition.

CONCLUSIONThese findings suggest that milk composition is generally weakly associated with maternal factors except for stage of lactation, and is likely to be more susceptible to long-term maternal nutritional status than short-term dietary fluctuation.

Adolescent ; Adult ; Body Mass Index ; Female ; Humans ; Lactation ; physiology ; Middle Aged ; Milk, Human ; chemistry ; Mothers ; Young Adult