UNASSIGNED: Incomplete monomer infiltration into the etched dentin causes postoperative sensitivity (POS) with total-etch adhesives. Increasing the temperature of the air to dry the adhesive has shown to improve its infiltration into the dentin.
UNASSIGNED: The aim of this research is to evaluate the effectiveness of dry air temperatures of 15°C ± 5°C and 50°C ± 5°C on the POS, depth of penetration, and bond strength of an ethanol/water-based etch-and-rinse (ER) adhesive under in vivo and in vitro conditions.
UNASSIGNED: Forty-four premolars from 11 patients scheduled for orthodontic extraction were allocated into cold air (Group 1) and warm air (Group 2) groups using a split-mouth design. A 2 mm × 2 mm × 2 mm cavity was prepared on the middle third of the buccal surface of the teeth, acid etched, and two coats of an ethanol/water-based adhesive resin mixed with 0.1% rhodamine B was applied for 10 s. A dental air gun customized to deliver warm and cold air was used to dry the adhesive prior to its light polymerization. The cavities were restored with resin composite incrementally. POS was assessed using visual analog scale at 24 and 72 h using cold test. The teeth were atraumatically extracted and analyzed for depth of adhesive penetration using confocal laser scanning microscope (n = 11) and push-out bond strength (n = 11).
UNASSIGNED: The data were analyzed using sample t-test and Wilcoxon signed-rank test (P < 0.05).
UNASSIGNED: A significantly lower POS and greater adhesive penetration into the dentin was observed in the warm air group compared to cold air (P < 0.05). No significant difference could be elicited between the push-out bond strength of both the groups (P > 0.05).
UNASSIGNED: Warm air alleviated POS and improved the penetration of an ethanol/water-based ER adhesive into the dentin.

In this study, the spatiotemporal variabilities and characteristics of ozone (O3) and fine particulate matter (PM2.5) were reconstructed, and the interaction between meteorological conditions and the co-occurrence of O3 and PM2.5 in Zhuhai, a city in the Pearl River Delta (China), was analysed. The vertical distributions of lower tropospheric O3, aerosol extinction coefficient, and wind velocity were measured using a ground-based LiDAR system. The diurnal variations in air pollutant concentrations and meteorological conditions at ground level were examined from 28 November to December 8, 2020 considering the weather conditions in Zhuhai. Heavy pollution episodes with increased concentrations of O3 and PM2.5 were observed from 6 to 7 December after a period of cold air invasion. The maximum hourly average concentrations of O3 and PM2.5 at the ground level reached up to 190 μg/m3, 98 μg/m3, respectively. The horizontal wind speed rapidly decreased to less than 2 m/s during the heavy pollution episodes driven by O3 and PM2.5, whereas the vertical wind velocity was dominated by the downdraught. When the large-scale synoptic winds were weak, a strengthening sea breeze in the afternoon could promote the landward propagation of warm marine air masses, and a lower surface wind speed was driven by the convergence of cold air from the north and warm air from the south. In turn, this increased the residence time of air pollutants and promoted their conversion to secondary pollutants. Regarding the pollution sources, the results indicated that the Pearl River Estuary represented a \'pool\' of O3 and PM2.5 pollution. In addition, the contribution of regional pollutant transport could not be ignored when considering the accumulative increase in air pollution. Overall, the relatively weak synoptic winds, low mixing height, and high generation of pollution around Zhuhai collectively resulted in high concentrations of O3 and PM2.5.

OBJECTIVE: The aim of this study is to review the evidence available suggesting that environmental conditions represent a risk factor associated with non-infective acute respiratory illness in athletes.
METHODS: Systematic review.
METHODS: PubMed, EBSCOhost and Web of Science (1st January 1990-31 July 2020) were searched systematically using keywords related to male and female athletes (i.e. from physically active individuals to elite athletes), aged 15-65 years and a combination of the terms (non-infective acute respiratory illness AND [pollution OR allergies OR climate] AND athletes AND prevalence/incidence/risk factors).
RESULTS: A total of seven papers (n = 1567 athletes) addressed our question. Among these, one focused on indoor air pollution, four on chlorinated swimming pool exposure and two on cold air conditions. None was selected for allergies, outdoor air pollution or other climatic conditions. Except rhinitis induced by swimming in chlorinated pools (n = 1), no respiratory disease due to the environment was identified specifically in athletes. The levels of chloramines in swimming pools (n = 2) and air pollutant in arenas (n = 1) were identified as risk factors for rhinitis and respiratory symptoms when exercising.
CONCLUSIONS: There is a paucity of data on the prevalence, incidence and risk factors of being acutely exposed to chlorine by-products, air pollution, cold air or altitude on the development of respiratory disease specifically in athletes. Noting the lack of a clear definition of environmentally induced lung disease in athletes, distinct from that of the general population, we addressed the few published management plans to protect athletes\' airways for each specific environment.

For centuries, cold temperatures have been used by humans for therapeutic, health and sporting recovery purposes. This application of cold for therapeutic purposes is regularly referred to as cryotherapy. Cryotherapies including ice, cold-water and cold air have been popularised by an ability to remove heat, reduce core and tissue temperatures, and alter blood flow in humans. The resulting downstream effects upon human physiologies providing benefits that include a reduced perception of pain, or analgesia, and an improved sensation of well-being. Ultimately, such benefits have been translated into therapies that may assist in improving post-exercise recovery, with further investigations assessing the role that cryotherapies can play in attenuating the ensuing post-exercise inflammatory response. Whilst considerable progress has been made in our understanding of the mechanistic changes associated with adopting cryotherapies, research focus tends to look towards the future rather than to the past. It has been suggested that this might be due to the notion of progress being defined as change over time from lower to higher states of knowledge. However, a historical perspective, studying a subject in light of its earliest phase and subsequent evolution, could help sharpen one\'s vision of the present; helping to generate new research questions as well as look at old questions in new ways. Therefore, the aim of this brief historical perspective is to highlight the origins of the many arms of this popular recovery and treatment technique, whilst further assessing the changing face of cryotherapy. We conclude by discussing what lies ahead in the future for cold-application techniques.

Regular exposure to a cold factor-cold water swimming or ice swimming and cold air-results in an increased tolerance to cold due to numerous adaptive mechanisms in humans. Due to the lack of scientific reports on the effects of extremely low outdoor temperatures on the functioning of the human circulatory system, the aim of this study was to evaluate complete blood count and biochemical blood indices in multiple Guinness world record holder Valerjan Romanovski, who was exposed to extremely cold environment from -5 °C to -37 °C for 50 days in Rovaniemi (a city in northern Finland). Valerjan Romanovski proved that humans can function in extremely cold temperatures. Blood from the subject was collected before and after the expedition. The subject was found to have abnormalities for the following blood indices: testosterone increases by 60.14%, RBC decreases by 4.01%, HGB decreases by 3.47%, WBC decreases by 21.53%, neutrocytes decrease by 17.31%, PDW increases by 5.31%, AspAT increases by 52.81%, AlAT increase by 68.75%, CK increases by 8.61%, total cholesterol decreases by 5.88%, HDL increases by 28.18%. Percentage changes in other complete blood count and biochemical indices were within standard limits. Long-term exposure of the subject (50 days) to extreme cold stress had no noticeable negative effect on daily functioning.

Although local cryotherapy (LC) is performed with various cooling agents (CAg) such as ice, water, and gasses, in clinical practice, it is mostly performed with cooling gasses. Presently, LC with cooling gasses is very popular but the inference about the thermal (stimulus) effect on the tissues is mainly based on research carried out using ice packs. The proposed objective of the study was to evaluate the dynamics of temperature changes in the knee joint area in response to a 3-min exposure to liquid nitrogen vapors (LNVs), cold air (CA) and ice bag (IB). The study group included 23 healthy volunteers with an average age of 26.67 ± 4.56. The exposed (ROIE) and contralateral (ROINE) areas of the knee joint after exposure to CAg were observed. Immediately after 3 min of LC, the ROIE temperature dropped by 10.11 ± 0.91 °C after LNV, 7.59 ± 0.14 °C after IB and 6.76 ± 1.3 °C after CA. Significant tissue cooling was maintained up to 15 min after LNV (p < 0.01), 10 min after IB (p < 0.05) and 5 min after CA (p < 0.05). LC causes significant temperature changes both in ROIE and ROINE. The greatest cooling potential was demonstrated for LNV and the lowest for CA.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) is considered an alternative marker of eosinophilic airway inflammation and is sometimes incorporated in the diagnosis of asthma. However, many patients with cough variant asthma (CVA) demonstrate an FeNO in the normal range. Therefore, additional information is needed to confirm the diagnosis of CVA, particularly in patients with low FeNO levels. We aimed to investigate the feasibility of using cough triggers to help diagnose CVA.
METHODS: We studied 163 patients presenting with prolonged/chronic cough alone (including 104 CVA patients) who underwent FeNO measurements and an airway responsiveness test, and answered a questionnaire listing 18 cough triggers. The sensitivity and specificity of FeNO levels and cough triggers for the diagnosis of CVA were determined.
RESULTS: CVA patients showed higher FeNO levels than non-CVA patients. When the cut-off value of FeNO levels for the diagnosis of CVA was set at 22ppb, its sensitivity was 57%. CVA patients more frequently responded to \"cold air\" and \"talking\" as cough triggers than non-CVA patients. When the analysis was confined to those with a low FeNO (<22ppb) group, the sensitivity and positive predictive values of \"cold air\" and \"talking\" for the diagnosis of CVA were 36% and 70% for \"cold air\", and 44% and 74% for \"talking\", respectively. Their specificity was 81%. \"Cold air\" was associated with airway hyperresponsiveness in all patients with an emphasis on those with low FeNO levels.
CONCLUSIONS: \"Cold air\" and/or \"talking\" as cough triggers could be signs for the diagnosis of CVA, particularly when FeNO levels are low.

Mucus overproduction is an important feature in patients with chronic inflammatory airway diseases and cold air stimulation has been shown to be associated with the severity of these diseases. However, the regulatory mechanisms that mediate excessive mucin production under cold stress remain elusive. Recently, the cold-inducible RNA-binding protein (CIRP) has been shown to be markedly induced after exposure to cold air. In this study, we sought to explore the expression of CIRP within bronchial biopsy specimens, the effect on mucin5AC (MUC5AC) production in chronic inflammatory airway diseases and the potential signaling pathways involved in cold air stimulation process. We found that CIRP protein expression was significantly increased in patients with COPD and in mice treated with cold air. Moreover, cold air stimulation induced MUC5AC expression in wild-type mice but not in CIRP(-/-) mice. In vitro, cold air stress significantly elevated the transcriptional and protein expression levels of MUC5AC in human bronchial epithelial cells. CIRP, toll-like receptor 4 (TLR4) and phosphorylated NF-κB p65 (p-p65) increased significantly in response to cold stress and CIRP siRNA, TLR4 - neutralizing Ab and a specific inhibitor of NF-κB could attenuated cold stress inducible MUC5AC expression. In addition, CIRP siRNA could hindered the expression levels of TLR4 and p-p65 both induced by cold stress. Taken together, these results suggest that airway epithelial cells constitutively express CIRP in vitro and in vivo. CIRP is responsible for cold-inducible MUC5AC expression by activating TLR4/NF-κB signaling pathway.

OBJECTIVE: To compare the effects of cold-water immersion (CWI) and whole-body cryotherapy (WBC) on recovery kinetics after exercise-induced muscle damage.
METHODS: Ten physically active men performed single-leg hamstring eccentric exercise comprising 5 sets of 15 repetitions. Immediately postexercise, subjects were exposed in a randomized crossover design to CWI (10 min at 10°C) or WBC (3 min at -110°C) recovery. Creatine kinase concentrations, knee-flexor eccentric (60°/s) and posterior lower-limb isometric (60°) strength, single-leg and 2-leg countermovement jumps, muscle soreness, and perception of recovery were measured. The tests were performed before and immediately, 24, 48, and 72 h after exercise.
RESULTS: Results showed a very likely moderate effect in favor of CWI for single-leg (effect size [ES] = 0.63; 90% confidence interval [CI] = -0.13 to 1.38) and 2-leg countermovement jump (ES = 0.68; 90% CI = -0.08 to 1.43) 72 h after exercise. Soreness was moderately lower 48 h after exercise after CWI (ES = -0.68; 90% CI = -1.44 to 0.07). Perception of recovery was moderately enhanced 24 h after exercise for CWI (ES = -0.62; 90% CI = -1.38 to 0.13). Trivial and small effects of condition were found for the other outcomes.
CONCLUSIONS: CWI was more effective than WBC in accelerating recovery kinetics for countermovement-jump performance at 72 h postexercise. CWI also demonstrated lower soreness and higher perceived recovery levels across 24-48 h postexercise.

Temperatures above and below what is generally regarded as \"comfortable\" for the human being have long been known to induce various airway symptoms, especially in combination with exercise in cold climate with temperatures below 0°C, which is naturally since exercise is followed by enhanced ventilation and thus greater amounts of inhaled cold air. The aim was to highlight the knowledge we have today on symptoms from the airways (here also including the eyes) arisen from various temperatures; the mechanisms, the pathophysiology and their clinical significance. The most common eye and airway conditions related to temperature changes are dry eye disease, rhinitis, laryngeal dysfunction, asthma, chronic obstructive pulmonary disease and chronic cough. Transient receptor potential (TRP) ion channels are probably involved in all temperature induced airway symptoms but via different pathways, which are now beginning to be mapped out. In asthma, the most persuasive hypothesis today is that cold-induced asthmatic bronchoconstriction is induced by dehydration of the airway mucosa, from which it follows that provocations with osmotic stimuli like hypertonic saline and mannitol can be used as a surrogate for exercise provocation as well as dry air inhalation. In chronic unexplained cough there seems to be a direct influence of cold air on the TRP ion channels followed by coughing and increased cough sensitivity to inhaled capsaicin. Revelations in the last decades of the ability of several airway TRP ion channels to sense and react to ambient air temperature have opened new windows for the understanding of the pathogenesis in a diversity of airway reactions appearing in many common respiratory diseases.