Heart Rate and Heart Rate Variability Response to the Transpiration of Vortex-Water byBegonia EliatorPlants to the Air in an Office During Visual Display Terminal Work

Effects of Indoor Plants on Human Functions: A Systematic Review with Meta-Analyses

The influences of indoor plants on people have been examined by only three systematic reviews and no meta-analyses. The objective of this study was therefore to investigate the effects of indoor plants on individuals' physiological, cognitive, health-related, and behavioral functions by conducting a systematic review with meta-analyses to fill the research gap. The eligibility criteria of this study were (1) any type of participants, (2) any type of indoor plants, (3) comparators without any plants or with other elements, (4) any type of objective human function outcomes, (5) any type of study design, and (6) publications in either English or Chinese. Records were extracted from the Web of Science (1990-), Scopus (1970-), WANFANG DATA (1980-), and Taiwan Periodical Literature (1970-). Therefore, at least two databases were searched in English and in Chinese-two of the most common languages in the world. The last search date of all four databases was on 18 February 2021. We used a quality appraisal system to evaluate the included records. A total of 42 records was included for the systematic review, which concluded that indoor plants affect participants' functions positively, particularly those of relaxed physiology and enhanced cognition. Separate meta-analyses were then conducted for the effects of the absence or presence of indoor plants on human functions. The meta-analyses comprised only 16 records. The evidence synthesis showed that indoor plants can significantly benefit participants' diastolic blood pressure (-2.526, 95% CI -4.142, -0.909) and academic achievement (0.534, 95% CI 0.167, 0.901), whereas indoor plants also affected participants' electroencephalography (EEG) α and β waves, attention, and response time, though not significantly. The major limitations of this study were that we did not include the grey literature and used only two or three records for the meta-analysis of each function. In brief, to achieve the healthy city for people's health and effective functioning, not only are green spaces needed in cities, but also plants are needed in buildings.

A unifying conceptual framework of factors associated to cardiac vagal control

Cardiac vagal control (CVC) reflects the activity of the vagus nerve regulating cardiac functioning. CVC can be inferred via heart rate variability measurement, and it has been positively associated to a broad range of cognitive, emotional, social, and health outcomes. It could then be considered as an indicator for effective self-regulation, and given this role, one should understand the factors increasing and decreasing CVC. The aim of this paper is to review the broad range of factors influencing CVC, and to provide a unifying conceptual framework to integrate comprehensively those factors. The structure of the unifying conceptual framework is based on the theory of ecological rationality, while its functional aspects are based on the neurovisceral integration model. The structure of this framework distinguishes two broad areas of associations: person and environment, as this reflects adequately the role played by CVC regarding adaptation. The added value of this framework lies at different levels: theoretically, it allows integrating findings from a variety of scientific disciplines and refining the predictions of the neurovisceral integration model; methodologically, it helps identifying factors that increase and decrease CVC; and lastly at the applied level, it can play an important role for society regarding health policies and for the individual to empower one's flourishing.

Abdominal breathing increases tear secretion in healthy women

PURPOSE

To determine the relationship between abdominal breathing and tear meniscus volume in healthy women, we investigated the change in tear meniscus volume in two groups: normal breathing and abdominal breathing.

METHODS

We used a crossover experimental model and examined 20 healthy women aged 20-54 years (mean ± SD, 32.7 ± 11.1 years). The participants were randomly assigned to one of two groups. During the first visit, the normal breathing group was subjected to normal breathing for 3 min, whereas the abdominal breathing group was subjected to abdominal breathing (4-second inhalation and 6-second exhalation) for 3 min. During the second visit, the protocols were swapped between the two groups. We estimated the R wave to R wave (R-R) interval, tear meniscus volume, salivary amylase activity, pulse, and blood pressure before and immediately after, 15 min after, and 30 min after completion of the breathing activity.

RESULTS

After abdominal breathing, compared to that before breathing, the tear meniscus volume increased significantly 15 min after breathing (P<.01). Furthermore, systolic blood pressure showed a significant decrease immediately after abdominal breathing (P<0.05). No significant difference was found in the test parameters in the normal breathing group.

CONCLUSION

Abdominal breathing for 3 minutes increases the tear meniscus volume in healthy women. Consequently, abdominal breathing may be considered in the treatment of dry eye disease.

ECG changes in factory workers exposed to 27.2 MHz radiofrequency radiation

To research the effect of 27.2 MHz radiofrequency radiation on electrocardiograms (ECG), 225 female workers operating radiofrequency machines at a shoe factory were chosen as the exposure group and 100 female workers without exposure from the same factory were selected as the control group. The 6 min electric field strength that the female workers were exposed to was 64.0 ± 25.2 V/m (mean ± SD), which exceeded 61 V/m, the International Commission on Non-Ionizing Radiation Protection reference root mean square levels for occupational exposure. A statistical difference was observed between the exposed group and the control group in terms of the rate of sinus bradycardia (χ(2)  = 11.48, P = 0.003). When several known risk factors for cardiovascular disease were considered, including smoking, age, alcohol ingestion habit, and so on, the exposure duration was not an effective factor for ECG changes, sinus arrhythmia, or sinus bradycardia according to α = 0.05, while P = 0.052 for sinus arrhythmia was very close to 0.05. We did not find any statistical difference in heart rate, duration of the QRS wave (ventricular depolarization), or corrected QT intervals (between the start of the Q wave and end of the T wave) between the exposed and control groups. Occupational exposure to radiofrequency radiation was not found to be a cause of ECG changes after consideration of the confounding factors.

Effects of functional water on heart rate, heart rate variability, and salivary immunoglobulin a in healthy humans: a pilot study

OBJECTIVE

This study was designed to explore the effects of drinking an average dietary volume of functional water on blood pressure, short-term cardiovascular variables, and salivary immunoglobulin A.

DESIGN

Subjects were studied in a randomized pre-post crossover design the morning after an overnight fast.

SUBJECTS

Fifteen (15) healthy nonsmoking subjects, 8 males and 7 females, aged between 15 and 49 years, participated in the study.

INTERVENTION

Short-term (10 minute) electrocardiography was measured in the participants before and after drinking either control mineral or functional water. The measurements were randomized, double blinded, and held two weeks apart. Saliva was collected for 4 minutes before the start of each electrocardiograph measurement. Blood pressure was monitored at 5 minute intervals for one hour as the mean of triplicate consecutive measurements.

RESULTS

Drinking 100 mL of control mineral or functional water did not alter arterial blood pressure in the 60 minutes post-drinking. Drinking control mineral water led to a significant fall in the heart rate, although all time domain and power density parameters remained unaffected. Consumption of functional water resulted in a significant difference in all time domain measures and in three of the power density parameters. The heart rate fell, while RR interbeat intervals, standard deviation of the normal-to-normal heartbeats (SDNN), and the square root of the mean squared differences of successive NN intervals (RMSSD) increased. A large rise in low (LF) and high frequency (HF) power had a significant effect on total power, indicating homeodynamic balance. Elevated LF power indicated intensified spectral power at frequencies in the range of 0.1 Hz, thus improving autonomic stability. The effect on the heart rate may confirm changes in cellular metabolism. Parasympathetic pathway activation stimulated secretory immunoglobulin A on mucosal surfaces, which protects against pathogenic invasion.

CONCLUSIONS

The drinking of functional water in healthy subjects elicited a rapid parasympathetic restorative response from the heart as well as stimulating mucosal humoral immunity. Functional water acts as an unconditional natural stimulus that elicits an involuntary response and facilitates physiological homeostasis.