The change of symptom clusters in gastric cancer patients during the perioperative period: a longitudinal study.

AIM AND OBJECTIVES: The purpose of this study was to describe the number, type and trajectory of symptom clusters during the perioperative period in patients with gastric cancer at four different time points. The study also aimed to identify the changes and consistency of these symptom clusters over time. DESIGN: This was a longitudinal study. METHODS: This study was conducted in a tertiary cancer hospital with 205 patients with gastric cancer. The M.D. Anderson Symptom Inventory Gastrointestinal Cancer Module was used to assess the incidence and severity of symptom clusters. Exploratory factor analysis was used to extract symptom clusters. RESULTS: The study identified four symptom clusters in patients with gastric cancer during the perioperative period: gastrointestinal symptom cluster, physical symptom cluster, psychological symptom cluster, and sleep disturbance symptom cluster. These clusters were observed across two to four time points. CONCLUSION: The findings of this study provide scientific evidence for medical staff and researchers to better understand the symptoms of patients with gastrointestinal cancer during the perioperative period. These findings can help develop individualized interventions for managing symptoms. RELEVANCE TO CLINICAL PRACTICE: Gastric cancer patients suffered from various symptom clusters, which lasted from one day before surgery to one month after surgery. They should be given careful consideration by clinical staff.

The Effectiveness of Symptom Management Theory in Guiding Clinical Practice-A Systematic Review.

Objective: Symptom Management Theory has been extensively used in guiding clinical practice to reduce patients' symptom burden, improve their outcomes and quality of life. However, concerning various participants, settings and methods, the effectiveness of practice and research based on the theory was inconsistent, which hindered the further implementation of this theory in clinical practice. Thus, this study aims to systematically evaluate the effectiveness of the Symptom Management Theory in guiding clinical practice. Methods: Systematic review. An online search of Chinese and English databases, including SinoMed, CNKI, WanFang Library, VIP database, MEDLINE, PubMed, Embase, Web of Science database, and Cochrane Library up to December 2023. This systematic review was conducted in accordance with the Joanna Briggs Institute critical appraisal checklist for randomized controlled trials and controlled clinical trials. The literature appraisal and extraction were independently conducted by two researchers. The third person was consulted if there was any disagreement between the two researchers. Results: A total of 20 articles (15 randomized controlled trials and five controlled clinical trials) were finally included. The overall quality of the articles was high. Additionally, the results showed that symptom management measurements based on the Symptom Management Theory could reduce the severity of patient's symptoms, alleviate their distress, relieve patients' anxiety and depression and improve their quality of sleep and quality of life. Conclusion: The Symptom Management Theory positively influenced clinical symptom management. It could provide theory-based symptom management methods in clinical practice to reduce patients' severity and burden of symptoms, level of anxiety, depression and distress. More high-quality original research should be conducted to further explore the theory's influence in guiding clinical practice in the future.

Indoor dryness and humidification-induced arsenic inhalation exposure above 4200 m in Ngari, China.

Ngari Prefecture, Tibet, China, features its ultrahigh altitude above 4200 m, very little annual precipitation and extremely low relative humidity. Residents who have migrated to Tibet from the plains use indoor humidification to reduce the respiratory discomfort caused by prolonged exposure to dry indoor air. In this study, field investigations and analysis of residential indoor environments and humidification methods in Ngari Prefecture revealed that ninety-eight percent of humidifier consumers in the prefecture used low-cost ultrasonic humidifiers filled with indoor tap water. The results revealed that the arsenic (As) concentration of the tap water was 41.6 µg/L, over four times China's standards for drinking water quality (10 µg/L). The source As concentration in the air humidified by the tap water-filled ultrasonic humidifier is (619.8 ± 59.1) (ng/m3 ·air), while no As was detected in the air humidified by the evaporative humidifier. For ultrasonic humidifier with tap water-filled, the inhalation dose of a healthy adult was 45.4 ng/d. The minute ventilation volume of migrated residents who had been in Ngari for less than two years (12.5 ± 4.3 L/min) was greater than those of the long-term residents (10.0 ± 4.5 L/min), which may exacerbate the short-term inhalation exposure risk for migrated residents. To reduce the health risks associated with As exposure, evaporative humidifiers are recommended for households using domestic water. If ultrasonic humidifiers are used, the tap water must be purified with terminal filters.

Exposure and respiratory infection risk via the short-range airborne route.

Leading health authorities have suggested short-range airborne transmission as a major route of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, there is no simple method to assess the short-range airborne infection risk or identify its governing parameters. We proposed a short-range airborne infection risk assessment model based on the continuum model and two-stage jet model. The effects of ventilation, physical distance and activity intensity on the short-range airborne exposure were studied systematically. The results suggested that increasing physical distance and ventilation reduced short-range airborne exposure and infection risk. However, a diminishing return phenomenon was observed when the ventilation rate or physical distance was beyond a certain threshold. When the infectious quantum concentration was less than 1 quantum/L at the mouth, our newly defined threshold distance and threshold ventilation rate were independent of quantum concentration. We estimated threshold distances of 0.59, 1.1, 1.7 and 2.6 m for sedentary/passive, light, moderate and intense activities, respectively. At these distances, the threshold ventilation was estimated to be 8, 20, 43, and 83 L/s per person, respectively. The findings show that both physical distancing and adequate ventilation are essential for minimising infection risk, especially in high-intensity activity or densely populated spaces.

Probable Evidence of Fecal Aerosol Transmission of SARS-CoV-2 in a High-Rise Building.

BACKGROUND: The role of fecal aerosols in the transmission of severe acute respiratory syndrome coronavirus 2 has been suspected. OBJECTIVE: To investigate the temporal and spatial distributions of 3 infected families in a high-rise apartment building and examine the associated environmental variables to verify the role of fecal aerosols. DESIGN: Epidemiologic survey and quantitative reverse transcriptase polymerase chain reaction analyses on throat swabs from the participants; 237 surface and air samples from 11 of the 83 flats in the building, public areas, and building drainage systems; and tracer gas released into bathrooms as a surrogate for virus-laden aerosols in the drainage system. SETTING: A high-rise apartment building in Guangzhou, China. PARTICIPANTS: 9 infected patients, 193 other residents of the building, and 24 members of the building's management staff. MEASUREMENTS: Locations of infected flats and positive environmental samples, and spread of virus-laden aerosols. RESULTS: 9 infected patients in 3 families were identified. The first family had a history of travel to the coronavirus disease 2019 (COVID-19) epicenter Wuhan, whereas the other 2 families had no travel history and a later onset of symptoms. No evidence was found for transmission via the elevator or elsewhere. The families lived in 3 vertically aligned flats connected by drainage pipes in the master bathrooms. Both the observed infections and the locations of positive environmental samples are consistent with the vertical spread of virus-laden aerosols via these stacks and vents. LIMITATION: Inability to determine whether the water seals were dried out in the flats of the infected families. CONCLUSION: On the basis of circumstantial evidence, fecal aerosol transmission may have caused the community outbreak of COVID-19 in this high-rise building. PRIMARY FUNDING SOURCE: Key-Area Research and Development Program of Guangdong Province and the Research Grants Council of Hong Kong.

Defining the sizes of airborne particles that mediate influenza transmission in ferrets.

Epidemics and pandemics of influenza are characterized by rapid global spread mediated by non-mutually exclusive transmission modes. The relative significance between contact, droplet, and airborne transmission is yet to be defined, a knowledge gap for implementing evidence-based infection control measures. We devised a transmission chamber that separates virus-laden particles by size and determined the particle sizes mediating transmission of influenza among ferrets through the air. Ferret-to-ferret transmission was mediated by airborne particles larger than 1.5 µm, consistent with the quantity and size of virus-laden particles released by the donors. Onward transmission by donors was most efficient before fever onset and may continue for 5 days after inoculation. Multiple virus gene segments enhanced the transmissibility of a swine influenza virus among ferrets by increasing the release of virus-laden particles into the air. We provide direct experimental evidence of influenza transmission via droplets and fine droplet nuclei, albeit at different efficiency.

Probable airborne transmission of SARS-CoV-2 in a poorly ventilated restaurant.

Although airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been recognized, the condition of ventilation for its occurrence is still being debated. We analyzed a coronavirus disease 2019 (COVID-19) outbreak involving three families in a restaurant in Guangzhou, China, assessed the possibility of airborne transmission, and characterized the associated environmental conditions. We collected epidemiological data, obtained a full video recording and seating records from the restaurant, and measured the dispersion of a warm tracer gas as a surrogate for exhaled droplets from the index case. Computer simulations were performed to simulate the spread of fine exhaled droplets. We compared the in-room location of subsequently infected cases and spread of the simulated virus-laden aerosol tracer. The ventilation rate was measured using the tracer gas concentration decay method. This outbreak involved ten infected persons in three families (A, B, C). All ten persons ate lunch at three neighboring tables at the same restaurant on January 24, 2020. None of the restaurant staff or the 68 patrons at the other 15 tables became infected. During this occasion, the measured ventilation rate was 0.9 L/s per person. No close contact or fomite contact was identified, aside from back-to-back sitting in some cases. Analysis of the airflow dynamics indicates that the infection distribution is consistent with a spread pattern representative of long-range transmission of exhaled virus-laden aerosols. Airborne transmission of the SARS-CoV-2 virus is possible in crowded space with a ventilation rate of 1 L/s per person.

Detection of Influenza and Other Respiratory Viruses in Air Sampled From a University Campus: A Longitudinal Study.

BACKGROUND: Respiratory virus-laden particles are commonly detected in the exhaled breath of symptomatic patients or in air sampled from healthcare settings. However, the temporal relationship of detecting virus-laden particles at nonhealthcare locations vs surveillance data obtained by conventional means has not been fully assessed. METHODS: From October 2016 to June 2018, air was sampled weekly from a university campus in Hong Kong. Viral genomes were detected and quantified by real-time reverse-transcription polymerase chain reaction. Logistic regression models were fitted to examine the adjusted odds ratios (aORs) of ecological and environmental factors associated with the detection of virus-laden airborne particles. RESULTS: Influenza A (16.9% [117/694]) and influenza B (4.5% [31/694]) viruses were detected at higher frequencies in air than rhinovirus (2.2% [6/270]), respiratory syncytial virus (0.4% [1/270]), or human coronaviruses (0% [0/270]). Multivariate analyses showed that increased crowdedness (aOR, 2.3 [95% confidence interval {CI}, 1.5-3.8]; P < .001) and higher indoor temperature (aOR, 1.2 [95% CI, 1.1-1.3]; P < .001) were associated with detection of influenza airborne particles, but absolute humidity was not (aOR, 0.9 [95% CI, .7-1.1]; P = .213). Higher copies of influenza viral genome were detected from airborne particles >4 µm in spring and <1 µm in autumn. Influenza A(H3N2) and influenza B viruses that caused epidemics during the study period were detected in air prior to observing increased influenza activities in the community. CONCLUSIONS: Air sampling as a surveillance tool for monitoring influenza activity at public locations may provide early detection signals on influenza viruses that circulate in the community.

Assessing the risk of downwind spread of avian influenza virus via airborne particles from an urban wholesale poultry market.

Interspecies transmissions of avian influenza viruses (AIV) occur at the human-poultry interface, among which the live poultry markets (LPMs) are easily assessed by urban residents. Thousands of live poultry from different farms arrive daily at wholesale markets before being sold to retail markets. We assessed the risk of AIV downwind spread via airborne particles from a representative wholesale market in Guangzhou. Air samples were collected using the cyclone-based NIOSH bioaerosol samplers at different locations inside a wholesale market, and viral RNA and avian 18S RNA were quantified using quantitative real-time RT-PCR. Computational Fluid Dynamics (CFD) modeling was performed to investigate the AIV spread pattern. Viral RNA was readily detected from 19 out of 21 air sampling events, predominantly from particles larger than 1 µm. The concentration of viral RNA detected at the poultry holding area was 4.4 × 105 copies/m3 and was as high as 2.6 × 104 copies/m3 100 m downwind. A high concentration of avian 18S RNA (2.5 × 108 copies/m3) detected at the poultry holding area was used for assessing the potential spread of avian influenza virus during outbreak situations. CFD modeling indicated the combined effect of wind direction and surrounding buildings on the spread of virus and a slow decay rate of the virus in the air in the downwind direction. Because of the large volume of poultry trade daily, wholesale markets located in urban areas may pose considerable AIV infection risk to neighboring residents via wind spread, even in the absence of direct contact with poultry.

Low re-inhalation of the exhaled flow during normal nasal breathing in a pediatric airway replica.

To estimate the fraction of the exhaled airflow that is re-inhaled during normal nasal breathing, experiments were carried out in a water tank with an anatomically accurate respiratory tract model of a 4-year-old child. The velocity of respiratory flow was scaled using similarity laws between air and water. Breath simulation was performed via a computer-controlled piston-cylinder system. Food-dye visualization allows a qualitative analysis of the re-inhaled fraction of this exhaled flow. For the quantitative analysis, neutrally buoyant particles were added to the water medium, and illuminated by the laser which illuminates the whole breathing region of the respiratory model, such that the trajectory and quantity of the re-inhaled particles can be recorded and counted. The experimental results in the pediatric airway replica show that a negligible fraction (<0.06%) of the exhaled airflow is re-inhaled during normal nasal breathing in the absence of the rising thermal plume. The artificial plume generated by a heated aluminium brick at the tank bottom increases the re-inhalation ratio by 4 times under the investigated case (albeit still at a very low value of 0.15%). Our results thus reveal that during normal nasal breathing in the present pediatric subject, the vast majority of human exhaled airflow escapes from the inhalation zone and is not re-inhaled.

Potential airborne transmission between two isolation cubicles through a shared anteroom.

Full-scale experiments and CFD simulations were performed to study potential inter-cubicle airborne transmissions through a shared anteroom due to the hinged door opening. When doors are closed, current negative pressure designs are effective for the containment of airborne pathogens in the 'dirty' cubicle with an index patient. When the 'dirty' cubicle door is open, airborne agents can move into the other 'clean' cubicle via the shared anteroom. As the door being opened or closed, the door sweeping effect is the main source of the two-way airflow and contaminant exchange through the doorway. When the dirty cubicle door remains fully open, temperature difference and concentration gradient across the doorway induce the two-way buoyancy-driven flow and transport of airborne agents across the doorway. The longer the dirty cubicle door remains fully open (10 s, 30 s or 60 s) or the smaller the air change rate (34-8.5 ACH for each cubicle), the more airborne pathogens are being transported into the 'clean' cubicle and the longer time it takes to remove them after the door is closed. Keeping the door completely open is potentially responsible for the majority of inter-cubicle transmissions if its duration is much longer than the duration of door motion (only 3 s). Our analyses suggest a potential inter-cubicle infection risk if the shared anteroom is used for multiple isolation cubicles. Decreasing the duration of door opening, raising air change rate or using a curtain at the doorway are recommended to reduce inter-cubicle exposure hazards.

Evaluating infection risks in buses based on passengers' dynamic temporal and typical spatial scenarios: A case study of COVID-19.

Conventional buses, as an indispensable part of the urban public transport system, impose cross-infection risks on passengers. To assess differential risks due to dynamic staying durations and locations, this study considered four spatial distributions (i = 1-4) and six temporal scenarios (j = 1-6) of buses. Based on field measurements and a risk assessment approach combining both short-range and room-scale effects, risks are evaluated properly. The results showed that temporal asynchrony between infected and susceptible individuals significantly affects disease transmission rates. The Control Case assumes that infected and susceptible individuals enter and leave synchronously. However, ignoring temporal asynchrony scenarios, i.e., the Control Case, resulted in overestimation (+30.7 % to +99.6 %) or underestimation (-15.2 % to -69.9 %) of the actual risk. Moreover, the relative difference ratios of room-scale risks between the Control Case and five temporal scenarios are impacted by ventilation. Short-range risk exists only if infected and susceptible individuals have temporal overlap on the bus. Considering temporal and spatial asynchrony, a more realistic total reproduction number (R) can be obtained. Subsequently, the total R was assessed under five temporal scenarios. On average, for the Control Case, the total R was estimated to be +27.3 % higher than j = 1, -9.3 % lower than j = 2, +12.8 % higher than j = 3, +33.0 % lower than j = 4, and + 77.6 % higher than j = 5. This implies the need for a combination of active prevention and real-time risk monitoring to enable rigid travel demand and control the spread of the epidemic.

Formation and toxicity contribution of chlorinated and dechlorinated halobenzoquinones from dichlorophenols after ozonation.

Halobenzoquinones (HBQs) are a class of disinfection byproducts with high cytotoxicity and potential carcinogenicity, which have been widely detected in chlorination of drinking water and swimming pool water. However, to date, the formation of HBQs upon ozonation and the HBQ precursors have been overlooked. This study investigated the formation of chlorinated and dechlorinated HBQs from six dichlorophenol (DCP) isomers. The monomeric and dimeric HBQs were identified in all the ozonation effluents, exhibiting 1-100 times higher toxicity levels than their precursors. The sum of detected HBQs intensity had a satisfactory linear relation with the maximum toxic unit (R2 = 0.9657), indicating the primary toxicity contribution to the increased overall toxicity of effluents. Based on density functional theory calculations, when ozone attacks the para carbon to the hydroxyl group of 2,3-DCP, the probability of producing chlorinated HBQs is 80.41 %, indicating that the para carbon attack mainly resulted in the formation of monomeric HBQs. 2,3-dichlorophenoxy radicals were successfully detected in ozonated 2,3-DCP effluent through electron paramagnetic resonance and further validated using theoretical calculation, revealing the formation pathway of dimeric HBQs. The results indicate that chlorinated phenols, regardless of the positions of chlorine substitution, can potentially serve as precursors for both chlorinated and dechlorinated HBQs formation during ozonation.

Continuous operation of nano-catalytic ozonation using membrane separation coupling system: Influence factors and mechanism.

The application of nano-catalysts in improving the ozonation removal efficiency for refractory organic compounds has been extensively investigated. However, cost-effective nano-catalysts separation remains a challenge. In this study, membrane separation processes were employed to separate nano-MgO catalysts from an ozonation system. A continuous nano-catalytic ozonation membrane separation (nCOMS) coupling system was successfully constructed for treating quinoline. The results showed that long hydraulic retention time (HRT) and high nano-MgO dosage could improve the quinolone removal efficiency but shorten operation cycles. At the optimal operation conditions of HRT = 4 h and nano-MgO dosage = 0.2 g/L, the nCOMS system achieved a stable quinoline removal efficiency of 85.2% for 240 min running with a transmembrane pressure lower than 10 kPa. The quinoline removal efficiency contribution for ozonation, catalysis and membrane separation was 57.1%, 24.9% and 18.0%, respectively. Compared to ozonation membrane separation system, the fouling rate index of the nCOMS system increased by 60% under optimal conditions, but the irreversible fouling was reduced to 28%. In addition, the nCOMS system exhibited reduced adverse effects of coexisting natural organic matter (NOM) on quinoline removal and membrane fouling. In conclusion, the nCOMS system demonstrated higher quinoline removal efficiency, lower irreversible fouling, and reduced adverse effect of coexisting NOM, thereby signifying its potential for practical applications in advanced treatment of industrial wastewater.

Tracing the origin of large respiratory droplets by their deposition characteristics inside the respiratory tract during speech.

Origin of differently sized respiratory droplets is fundamental for clarifying their viral loads and the sequential transmission mechanism of SARS-CoV-2 in indoor environments. Transient talking activities characterized by low (0.2 L/s), medium (0.9 L/s), and high (1.6 L/s) airflow rates of monosyllabic and successive syllabic vocalizations were investigated by computational fluid dynamics (CFD) simulations based on a real human airway model. SST k-ω model was chosen to predict the airflow field, and the discrete phase model (DPM) was used to calculate the trajectories of droplets within the respiratory tract. The results showed that flow field in the respiratory tract during speech is characterized by a significant laryngeal jet, and bronchi, larynx, and pharynx-larynx junction were main deposition sites for droplets released from the lower respiratory tract or around the vocal cords, and among which, over 90% of droplets over 5 µm released from vocal cords deposited at the larynx and pharynx-larynx junction. Generally, droplets' deposition fraction increased with their size, and the maximum size of droplets that were able to escape into external environment decreased with the airflow rate. This threshold size for droplets released from the vocal folds was 10-20 µm, while that for droplets released from the bronchi was 5-20 µm under various airflow rates. Besides, successive syllables pronounced at low airflow rates promoted the escape of small droplets, but do not significantly affect the droplet threshold diameter. This study indicates that droplets larger than 20 µm may entirely originate from the oral cavity, where viral loads are lower; it provides a reference for evaluating the relative importance of large-droplet spray and airborne transmission route of COVID-19 and other respiratory infections.

Numerical investigation of impinging jet ventilation in ICUs: Is thermal stratification a problem?

Intensive care units (ICUs) are the high incidence sites of hospital-acquired infections, where impinging jet ventilation (IJV) shows great potential. Thermal stratification of IJV and its effect on contaminants distribution were systematically investigated in this study. By changing the setting of heat source or the air change rates, the main driving force of supply airflow can be transformed between thermal buoyancy and inertial force, which can be quantitatively described by the dimensionless buoyant jet length scale (lm¯). For the investigated air change rates, namely 2 ACH to 12 ACH, lm¯ varies between 0.20 and 2.80. The thermal buoyancy plays a dominant role in the movement of the horizontally exhaled airflow by the infector under low air change rate, where the temperature gradient is up to 2.45 °C/m. The flow center remains close to the breathing zone of the susceptible ahead, resulting into the highest exposure risk (6.6‰ for 10-µm particles). With higher heat flux of four PC monitors (from 0 W to 125.85 W for each monitor), the temperature gradient in ICU rises from 0.22 °C/m to 1.02 °C/m; however, the average normalized concentration of gaseous contaminants in the occupied zone is reduced from 0.81 to 0.37, because their thermal plumes are also able to carry containments around them to the ceiling-level readily. As the air change rate was increased to 8 ACH (lm¯=1.56), high momentum weakened the thermal stratification by reducing the temperature gradient to 0.37 °C/m and exhaled flow readily rose above the breathing zone; the intake fraction of susceptible patient located in front of the infector for 10-µm particles reduces to 0.8‰. This study proved the potential application of IJV in ICUs and provides theoretical guidance for its appropriate design.}.

Redox-directed identification of toxic transformation products during ozonation of aromatics.

The toxicity assessment of transformation products (TPs) formed in oxidative water treatment is crucial but challenging because of their low concentration, structural diversity, and mixture complexity. Here, this study developed a novel redox-directed approach for identification of toxic TPs without the individual toxicity and concentration information. This approach based on sodium borohydride reduction comprised an integrated process of toxicological evaluation, fluorescence excitation-emission matrix characterization, high-resolution mass spectrometry detection, followed by ecological toxicity assessment of identified TPs. The redox-directed identification of primary causative toxicants was experimentally tested for the increased nonspecific toxicity observations in the ozonated effluents of model aromatics. Reduction reaction caused a remarkable decrease in toxicity and increase in fluorescence intensity, obtaining a good linear relation between them. More than ten monomeric or dimeric p-benzoquinone (p-BQ) TPs were identified in the ozonated effluents. The occurrence of the p-BQ TPs was further verified through parallel sodium sulfite reduction and actual wastewater ozonation experiments. In vitro bioassays of luminescent bacteria, as well as in silico genotoxicity and cytotoxicity predictions, indicate that the toxicity of p-BQ TPs is significantly higher than that of their precursors and other TPs. These together demonstrated that the identified p-BQ TPs are primary toxicity contributors. The redox-directed approach facilitated the revelation of primary toxicity contribution, illustrating emerging p-BQs are a concern for aquatic ecosystem safety in the oxidative treatment of aromatics-contaminated wastewater.

Effects of individualized dietary counseling on nutritional status and quality of life in post-discharge patients after surgery for gastric cancer: A randomized clinical trial.

Background: Currently, the supporting evidence for dietary counseling is insufficient. The aim of this study is to evaluate the impact of individualized dietary counseling on nutritional outcomes and quality of life (QOL) in patients undergoing surgery for gastric cancer. Methods: This study was a prospective, single-center, randomized controlled trial. The patients after surgery for gastric cancer were randomly assigned (1:1) to the intervention group and the control group. In the intervention group, patients receive individualized dietary counseling based on individual calorie needs and symptom assessment at 24 h before discharge, 14, 21, 30, and 60 days postoperatively. Patients in the control group received routine dietary counseling. The primary endpoint was body mass index (BMI) loss at 30, 60, and 90 days after surgery; the secondary endpoints were calorie and protein intake at 30 and 60 days after surgery, blood parameters, the 90-day readmission rate, and QOL at 90 days after surgery. Results: One hundred thirty patients were enrolled; 67 patients were assigned to the intervention group and 63 patients to the control group. Compared with the control group, patients in the intervention group were significantly less BMI loss at 30 days (-0.84 ± 0.65 vs. -1.29 ± 0.83), 60 days (-1.29 ± 0.92 vs. -1.77 ± 1.13), and 90 days (-1.37 ± 1.05 vs. -1.92 ± 1.66) after surgery (all P< 0.05). Subgroups analysis by surgery type showed that the intervention could significantly reduce BMI loss in patients undergoing total and proximal gastrectomy at 30 days (-0.75 ± 0.47 vs. -1.55 ± 1.10), 60 days (-1.59 ± 1.02 vs. -2.55 ± 1.16), and 90 days (-1.44 ± 1.19 vs. -3.26 ± 1.46) after surgery (all P< 0.05). At 60 days after surgery, calorie goals were reached in 35 patients (77.8%) in the intervention group and 14 patients (40.0%) in the control group (P = 0.001), and protein goals were reached in 40 patients (88.9%) in the intervention group and 17 patients (48.6%) in the control group (P< 0.001). Regarding the QOL at 90 days after surgery, the patients in the intervention group had a significantly lower level of fatigue, shortness of breath and stomach pain, better physical function, and cognitive function (P< 0.05). Conclusions: Post-discharge individualized dietary counseling is an effective intervention to reduce post-gastrectomy patient weight loss and to elevate calorie intake, protein intake, and QOL.

Close contact behaviors of university and school students in 10 indoor environments.

Close contact routes, including short-range airborne and large-droplet routes, play an important role in the transmission of SARS-CoV-2 in indoor environments. However, the exposure risk of such routes is difficult to quantify due to the lack of data on the close contact behavior of individuals. In this study, a digital wearable device, based on semi-supervised learning, was developed to automatically record human close contact behavior. We collected 337,056 s of indoor close contact of school and university students from 194.5 h of depth video recordings in 10 types of indoor environments. The correlation between aerosol exposure and close contact behaviors was then evaluated. Individuals in restaurants had the highest close contact ratio (64%), as well as the highest probability of face-to-face pattern (78%) during close contact. Accordingly, university students showed greater exposure potential in dormitories than school students in homes, however, a lower exposure was observed in classrooms and postgraduate student offices in comparison with school students in classrooms. In addition, restaurants had the highest aerosol exposure volume for both short-range inhalation and direct deposition on the facial mucosa. Thus, the classroom was established as the primary indoor environment where school students are exposed to aerosols.