Biomedical subjects

Cheryl C H Yang

Publications and source records attributed to Cheryl C H Yang.

At least 19 recordsLinked to original sources

PubMed2006

Effects of long-term vegetarian diets on cardiovascular autonomic functions in healthy postmenopausal women.

The incidence of cardiovascular disease is higher in postmenopausal women than in premenopausal women. We hypothesized that long-term vegetarian diets might modulate cardiovascular autonomic functions measured by frequency-domain techniques in healthy postmenopausal women. A total of 35 healthy vegetarians (mean age +/- SEM 55.0 +/- 1.3 years) who had been vegetarians for > or =2 years and 35 omnivores (55.1 +/- 1.4 years) participated in this study. These subjects were all postmenopausal without hormone replacement therapy. Fluctuations in arterial blood pressure and heart rate variability were diffracted into low-frequency (0.04 to 0.15 Hz) and high-frequency (0.15 to 0.4 Hz) segments. Cardiovascular autonomic functions and baroreflex sensitivity were evaluated by specific frequency-domain measures. The vegetarians had statistically lower systolic and diastolic blood pressure, and lower serum total cholesterol, low-density lipoprotein cholesterol, triglycerides, fasting blood sugar, and hemoglobin levels compared with the nonvegetarians. They also exhibited a significantly higher high-frequency power of heart rate variability and increased baroreflex sensitivity than did omnivores. No statistical differences were found in the low-frequency/high-frequency ratio or percentage of low frequency of heart rate variability between the 2 groups. In conclusion, in addition to the lower blood pressure and lipid concentrations in vegetarians, long-term vegetarian diets may facilitate vagal regulation of the heart and increase baroreflex sensitivity in healthy postmenopausal women, without increasing the sympathetic modulations of the cardiovascular system.

Autonomic Nervous System↗

PubMed2006

Cardiac autonomic regulation differentiates reflux disease with and without erosive esophagitis.

OBJECTIVE: Impaired autonomic function has been observed in patients with gastroesophageal reflex disease (GERD), but little is known about autonomic function in patients with non-erosive reflux disease (NERD). The objective of this study was to investigate potential differences in autonomic function by means of heart rate variability in GERD patients with and without erosive esophagitis. MATERIAL AND METHODS: Thirty-five GERD patients and 20 healthy controls participated in the study. Seventeen subjects with NERD and 18 patients with erosive reflux disease (ERD) were identified based on typical reflux symptoms, endoscopic findings, and 24-h esophageal pH. Spectral analysis of heart rate variability was performed to calculate the low-frequency (LF) band, the high-frequency (HF) band, and the LF/HF ratio. RESULTS: No significant differences were found in age, gender, body mass index, or current tobacco use among the reflux patients and controls. The Helicobacter pylori status and severity of reflux symptoms were similar between the two groups. The HF band power was significantly lower in patients with ERD than in NERD patients (p < 0.01) and controls (p < 0.05). LF band power (%) and LF/HF ratio were significantly lower in the NERD patients compared with ERD patients (p < 0.05) and controls (p < 0.05). There was no statistically significant correlation between any heart rate variability parameter and symptom severity score in either the ERD or NERD group. CONCLUSIONS: Patients with ERD and NERD display a similar degree of symptom severity, but the pattern of autonomic function appears to differ between NERD and ERD.

Adult↗

PubMed2006

Cardiac autonomic dysregulation in patients with acute hepatitis.

BACKGROUND: Autonomic dysfunction is common in patients with chronic liver disease, but it is still unclear whether acute hepatitis coincides with alterations in autonomic functions. METHODS: We evaluated the heart rate variability (HRV) of 10 patients with acute hepatitis (6 males, 4 females; mean age, 44.0 y; range, 20-69 y). Frequency-domain analysis of short-term and stationary R-R intervals was performed on the first day of admission to detect low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF, 0.15-0.40 Hz), the ratio of LF to HF (LF/HF), and LF in normalized units (LF%). The same measurement was repeated on the 7th day of admission. RESULTS: We found that there was a significant increase of HF as well as variance of the R-R interval on the 7th day after admission (P < 0.05). There was a significant negative correlation between HF and the change of total bilirubin (P < 0.05). CONCLUSIONS: The study demonstrates a change in cardiac vagal tone associated with acute hepatitis by analysis of HRV, and such alteration is less pronounced later during the clinical course of acute hepatitis.

Acute Disease↗

PubMed2006

Time course of cardiovascular neural regulation during programmed 20-sec apnea in rats.

OBJECTIVES: Long-term hypoxia results in hemodynamic breakdown in patients in the intensive care unit; however, intermittent hypoxia causes hypertension in individuals with sleep apnea. The objective of this study was to explore the sequential cardiovascular neural alterations in response to acute hypoxic apnea. DESIGN: The authors conducted a prospective, randomized animal study. SETTING: The study was conducted in a university animal laboratory. METHODS: A programmable apnea model was developed in anesthetized rats, in which a 20-sec period of apnea was produced and subsequently divided into the early (2.0 to 7.9 secs), middle (8.0 to 13.9 secs), and late apneic phases (14.0 to 19.9 secs) and immediate reventilatory phase (20.0 to 25.9 secs). RESULTS: Evident hypoxia developed during 20-sec apnea. Arterial pressure increased in the early apneic phase and returned to control level in the middle phase. Significant hypotension developed in the late apneic phase and deteriorated in the reventilatory phase. Interbeat interval increased mildly along the apneic event. The increase of pressure in the early and middle phases was inhibited by propranolol (1.0 mg/kg intravenously [iv]) but was provoked by phentolamine (2.5 mg/kg iv). The decrease of pressure in the late and reventilatory phases was reversed, at least in part, by phentolamine. Atropine (0.5 mg/kg iv) did not produce discernible effects in the arterial pressure. The increase of interbeat interval was suppressed by propranolol. Power spectral analysis of arterial pressure variability demonstrated significant increases of the low-frequency (sympathetic vasomotor activity) and normalized high-frequency (cardiac sympathetic modulation) power after reventilation. CONCLUSION: Although the sympathetic activity is excited during and after a hypoxic apnea, the immediate pressor effect is related to an inotropic response of cardiac sympathetic regulation, whereas the negative chronotropic and subsequent depressor effect is associated with a failure in the cardiovascular response to sympathetic excitation.

Analysis of Variance↗

PubMed2006

Voice low tone to high tone ratio: a potential quantitative index for vowel [a:] and its nasalization.

Hypernasality is associated with various diseases and interferes with speech intelligibility. A recently developed quantitative index called voice low tone to high tone ratio (VLHR) was used to estimate nasalization. The voice spectrum is divided into low-frequency power (LFP) and high-frequency power (HFP) by a specific cutoff frequency (600 Hz). VLHR is defined as the division of LFP into HFP and is expressed in decibels. Voice signals of the sustained vowel [a :] and its nasalization in eight subjects with hypernasality were collected for analysis of nasalance and VLHR. The correlation of VLHR with nasalance scores was significant (r = 0.76, p < 0.01), and so was the correlation between VLHR and perceptual hypernasality scores (r = 0.80, p < 0.01). Simultaneous recordings of nasal airflow temperature with a thermistor and voice signals in another 8 healthy subjects showed a significant correlation between temperature rate of nasal airflow and VLHR (r = 0.76, p < 0.01), as well. We conclude that VLHR may become a potential quantitative index of hypernasal speech and can be applied in either basic or clinical studies.

Adult↗

PubMed2005

Sleep-related vagotonic effect of zolpidem in rats.

RATIONALE: Zolpidem is a relatively new nonbenzodiazepine sedative-hypnotic. The effects of zolpidem on autonomic functions remain unclear. OBJECTIVES: The aim of this study was to evaluate the effects of zolpidem on sleep and related cardiac autonomic modulations as compared with triazolam in Wistar-Kyoto rats. METHODS: Continuous power spectral analyses of electroencephalogram (EEG), electromyogram, and heart rate variability were performed on freely moving rats during daytime sleep. The consciousness states were classified into active waking (AW), quiet sleep (QS), and paradoxical sleep (PS). Drugs were administered via gavage and data within 2 h were analyzed. RESULTS: All zolpidem (ZP3, 3 mg/kg; ZP30, 30 mg/kg) and triazolam (TZ0.075, 0.075 mg/kg; TZ0.75, 0.75 mg/kg) groups had longer accumulated QS time and averaged QS duration as compared with the vehicle control. The accumulated QS time and averaged QS duration of ZP3 were similar to those of TZ0.075. Significant suppressions of PS time were noted in all drug groups except ZP3. During QS, ZP3 and ZP30 exhibited significant increases of magnitude and percentage of EEG delta power, whereas TZ0.075 and TZ0.75 did not. Heart period and high-frequency power of heart rate variability increased significantly in ZP3 during all sleep-wake states. Both parameters, however, did not increase but even decreased in ZP30, TZ0.075, and TZ0.75. CONCLUSIONS: Zolpidem not only caused a longer and deeper sleep but also led to an elevated cardiac vagal activity at a specific dose in the rat.

Animals↗

PubMed2005

Sleep-related changes in cardiovascular neural regulation in spontaneously hypertensive rats.

BACKGROUND: Sleep has significant effects on cardiovascular neural regulation. The aim of this study is to explore the possible change in sympathetic vasomotor activity and baroreflex sensitivity associated with spontaneous hypertension during each stage of the sleep-wake cycle. METHODS AND RESULTS: Polysomnographic analysis was performed in freely moving spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) during their normal daytime sleep. Continuous spectral analyses of electroencephalogram and electromyogram were performed to define active waking, quiet sleep, and paradoxical sleep. Low-frequency power of the arterial pressure variability (BLF) was quantified to provide an index of sympathetic vasomotor activity. Spontaneous baroreflex sensitivity was assessed (1) by the slopes of the regression lines of the mean arterial pressure and R-R intervals pairs that ascended (BrrA) or descended (BrrD) successively and (2) by the magnitudes of the arterial pressure and R-R intervals transfer functions in the high-frequency (BrrHF) or low-frequency (BrrLF) ranges. SHR had significantly higher mean arterial pressure during each of the sleep-wake states. Although the values of BLF, BrrA, BrrD, BrrHF, and BrrLF in SHR did not differ from those of WKY during active waking, SHR had a significantly higher BLF and lower BrrA, BrrD, BrrHF, and BrrLF compared with WKY during quiet sleep and paradoxical sleep. CONCLUSIONS: SHR had enhanced sympathetic vasomotor activity but attenuated baroreflex sensitivity during sleep although each phenomenon was not evident when awake.

Animals↗

PubMed2005

Effects of different classes of antihypertensive drugs on cerebral hemodynamics in elderly hypertensive patients.

BACKGROUND: This study was designed to estimate the effect of different classes of antihypertensive drugs on cerebral hemodynamics in elderly stroke-free, nondiabetic hypertensive patients by applying frequency-domain techniques. METHODS: A total of 60 hypertensive patients divided into treatment groups of 15 unmedicated (HT), 15 nifedepine sustained release form (CCB), 15 atenolol (BB), and 15 valsartan (AIIA), and 15 age-matched healthy volunteers (CON) were studied prospectively. Variability of arterial blood pressure (ABP) and middle cerebral artery flow velocity (MCAFV) detected by transcranial Doppler sonography were diffracted into very-low frequency (VLF, 0.016 to 0.04 Hz), low frequency (LF, 0.04 to 0.15 Hz), and high frequency (HF, 0.15 to 0.4 Hz). Cerebral hemodynamics was quantified by the ABP-MCAFV transfer function. RESULTS: The ABP and MCAFV were statistically different between CON and HT groups, but not significantly different among CON, CCB, BB, and AIIA groups. The LF phase and HF magnitude in the HT, CCB, and BB groups were significantly attenuated than in those of the CON group, but not statistically different between the AIIA and CON groups. There was no statistical difference in VLF and LF transfer magnitude among the five groups. CONCLUSIONS: Although cerebral vasomotor reserve and cerebral blood flow are impaired in unmedicated hypertensive patients, the cerebral autoregulatory response was preserved both in controlled and uncontrolled hypertension. Nifedipine, atenolol, and valsartan are all effective as monotherapy to control ABP and restore cerebral blood flow. Valsartan has the effect to normalize the changes in cerebral vasomotor reserve to a level similar as in age-matched healthy subjects.

Adrenergic beta-Antagonists↗

PubMed2005

Effect of nasal decongestion on voice spectrum of a nasal consonant-vowel.

The nasal cavity and its related structures make significant contributions to human phonation, especially the resonance of voice spectra. The voice spectra of the nasal consonant-vowel (CV), [md:], in the subjects with nasal obstruction were obtained and were compared with the spectra of the same CV vocalized by the same subjects after topical nasal decongestion treatment with 1:1000 epinephrine solution. Results revealed that the intensity damping was more marked in the high-frequency area (>1600 Hz) after the nasal decongestion. Moreover, the intensities of the spectral valleys damped more than the spectral peaks, especially the spectral valley of 1000-2700 Hz. Therefore, a more complex spectral pattern was formed by the resultant uneven damping effect after nasal decongestion. The nasal cavity plays an important role in the formation of spectral peaks and valleys, and such engraved voice spectra may also characterize nasal voices like the nasal CV [md:] demonstrated in our study.

Adolescent↗

PubMed2005

Regression analysis between heart rate variability and baroreflex-related vagus nerve activity in rats.

INTRODUCTION: Many previous studies have suggested that the high-frequency (HF) power of the heart rate variability may represent cardiac vagal activity although direct evidence of a correlation between the HF and vagal neuronal activity is still lacking. In the present study, we performed a regression analysis of the HF and vagal neurograms. METHODS AND RESULTS: Experiments were carried out on adult male Sprague-Dawley rats anesthetized with a continuous infusion of pentobarbital sodium. The baroreflex-related vagus neuronal activities were obtained by nerve or single-fiber recordings. The transient baroreflex response was employed to alter vagus neuronal activities using a bolus injection of phenylephrine (PE). On-line power spectral analysis of the heart rate and a vagal neurogram was performed during the acute baroreflex response. During the test period, systemic arterial pressure immediately increased in response to the PE injection, after which the R-R interval (RR), HF (0.6-2.4 Hz), and vagus nerve and unit activities all dramatically increased. Both nerve and unit activities exhibited good correlations (r > or = 0.7 in all nerve recordings and r > or = 0.6 in 91% of single-fiber recordings) with the HF. There were insignificant differences between the right- and left-side baroreflex-related vagus nerve recordings. CONCLUSION: Our present study provides a direct linkage between the HF and vagus neuronal electrical activity in anesthetized rats.

Animals↗

PubMed2004

Scatterplot analysis of EEG slow-wave magnitude and heart rate variability: an integrative exploration of cerebral cortical and autonomic functions.

STUDY OBJECTIVES: To explore interactions between cerebral cortical and autonomic functions in different sleep-wake states. DESIGN: Active waking (AW), quiet sleep (QS), and paradoxical sleep (PS) of adult male Wistar-Kyoto rats (WKY) on their daytime sleep were compared. PARTICIPANTS: Ten WKY. INTERVENTIONS: All rats had electrodes implanted for polygraphic recordings. One week later, a 6-hour daytime sleep-wakefulness recording session was performed. MEASUREMENTS AND RESULTS: A scatterplot analysis of electroencephalogram (EEG) slow-wave magnitude (0.5-4 Hz) and heart rate variability (HRV) was applied in each rat. The EEG slow-wave-RR interval scatterplot from all of the recordings revealed a propeller-like pattern. If the scatterplot was divided into AW, PS, and QS according to the corresponding EEG mean power frequency and nuchal electromyogram, the EEG slow wave-RR interval relationship became nil, negative, and positive for AW, PS, and QS, respectively. A significant negative relationship was found for EEG slow-wave and high-frequency power of HRV (HF) coupling during PS and for EEG slow wave and low-frequency power of HRV to HF ratio (LF/HF) coupling during QS. The optimal time lags for the slow wave-LF/HF relationship were different between PS and QS. CONCLUSIONS: Bradycardia noted in QS and PS was related to sympathetic suppression and vagal excitation, respectively. The EEG slow wave-HRV scatterplot may provide unique insights into studies of sleep, and such a relationship may delineate the sleep-state-dependent fluctuations in autonomic nervous system activity.

Animals↗

PubMed2004

Changes in sleep patterns in spontaneously hypertensive rats.

STUDY OBJECTIVES: To explore whether spontaneous hypertension is associated with a change in sleep pattern in rats. DESIGN: Adult male spontaneously hypertensive rats (SHR) were compared to normotensive Wistar-Kyoto rats (WKY) on their normal daytime sleep pattern. PARTICIPANTS: Ten WKY and 10 SHR. INTERVENTIONS: All rats had electrodes implanted for polygraphic recordings. Weeks later, a 5-hour daytime sleep-weakfulness recording session was analyzed. MEASUREMENTS AND RESULTS: Electroencephalogram and electromyogram signals were subjected to continuous power spectral analysis, from which mean power frequency of the electroencephalogram and power of the electromyogram were quantified. Active waking (AW), quiet sleep (QS), and paradoxical sleep (PS) were defined every 8 seconds from corresponding mean power frequency and electromyogram power readings. Analysis of heart-rate variability was derived from the electrocardiogram signals. Macrostructural analysis of sleep revealed that SHR were characterized by fewer QS and PS episodes and eventually shorter accumulated QS and PS times as compared to WKY. SHR also had more QS-to-AW transitions but fewer QS-to-PS transitions. Microstructural analysis revealed that SHR were associated with more-frequent interruptions during QS. Analysis of heart-rate variability indicated that SHR had similar R-R intervals and lower high-frequency (0.6-2.4 Hz) power but a higher ratio of low-frequency (0.06-0.6 Hz) power to high-frequency power during the daytime recording as compared to WKY. CONCLUSIONS: As compared to WKY, SHR may have less sleep time, poorer sleep quality, and a greater tendency to wake up from QS. Such changes in sleep may be concomitant with cardiac autonomic changes. Our methodology offers a convenient yet effective way to study the constitution, sequence, and interruption of sleep in the rat.

Animals↗

PubMed2004

Transfer function analysis of heart rate variability in response to water intake: correlation with gastric myoelectrical activity.

We utilized transfer function analysis of heart rate variability (HRV) and respiration to investigate the effect of water intake on gastric myoelectrical activity and its relationship to vagal activity. The electrogastrography (EGG) and HRV were recorded simultaneously before and after drinking 500 ml of water in 10 healthy subjects. We observed good linearity between lung volumes and HRV signals at a ventilatory rate between 0.2 and 0.4 Hz before and after water intake. The EGG power of 3 cycles/min increased remarkably after the water intake. We found that there was a significant increase in the magnitude of the respiration-HRV transfer function after water intake (P < 0.05). The EGG 3 cycles/min power was positively correlated with the transfer magnitude throughout the study (r = 0.54, P = 0.01). These results confirm that transfer function analysis of HRV sensitively identifies subtle changes in the respiratory sinus arrhythmia that occurs with water intake. The present findings suggest that transfer function analysis of HRV and respiration after water intake can be used to evaluate vagal nervous activity in the human gut.

Adult↗

PubMed2004

Effect of esmolol on positive-pressure ventilation-induced variations of arterial pressure in anaesthetized humans.

Positive-pressure ventilation-induced variations in arterial pressure have been related to cardiac sympathetic activity in animals. However, the effect of beta-adrenoceptor blockade on these variations in anaesthetized humans under positive-pressure ventilation has not yet been investigated. In the present study, RAPV (respiratory-related arterial pressure variability) and %SPV (percentile systolic pressure variation) were determined before and after esmolol treatment in ten mechanically ventilated patients. RAPV and %SPV decreased significantly after intravenous esmolol (1 mg/kg of body weight) treatment (maximal decrease of RAPV, 50% and %SPV, 35%). Linear regression analysis of RAPV and %SPV before and after esmolol treatment both revealed high correlation (r = 0.93 and 0.91 respectively). The amplitudes of RAPV and %SPV also significantly increased in a graded way with higher tidal volumes. Thus we propose that esmolol suppresses the variations in arterial pressure induced by positive-pressure mechanical ventilation, and we suggest that RAPV and %SPV may be alternative choices for monitoring cardiac sympathetic regulation in anaesthetized patients under positive-pressure ventilation.

Adrenergic beta-Antagonists↗

PubMed2003

Sleep-related sympathovagal imbalance in SHR.

The role of the autonomic nervous system in spontaneous hypertension during each stage of the sleep-wake cycle remains unclear. The present study attempted to evaluate the differences in cardiac autonomic modulations among spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY), and Sprague-Dawley rats (SD) across sleep-wake cycles. Continuous power spectral analysis of electroencephalogram, electromyogram, and heart rate variability was performed in unanesthetized free moving rats during daytime sleep. Frequency-domain analysis of the stationary R-R intervals (RR) was performed to quantify the high-frequency power (HF), low-frequency power (LF)-to-HF ratio (LF/HF), and normalized LF (LF%) of heart rate variability. WKY and SD had similar mean arterial pressure, which is significantly lower than that of SHR during active waking, quiet sleep, and paradoxical sleep. Compared with WKY and SD, SHR had lower HF but similar RR, LF/HF, and LF% during active waking. During quiet sleep, SHR developed higher LF/HF and LF% in addition to lower HF. SHR ultimately exhibited significantly lower RR accompanied with higher LF/HF and LF% and lower HF during paradoxical sleep compared with WKY. We concluded that significant cardiac sympathovagal imbalance with an increased sympathetic modulation occurred in SHR during sleep, although it was less evident during waking.

Animals↗

PubMed2003

Voice low tone to high tone ratio--a new index for nasal airway assessment.

There are several methodology based on voice analysis to evaluate nasal airway. Here we introduce a new quantitative index based on voice spectrum analysis to evaluate nasal obstruction. Ten subjects of nasal blockage were instructed to produced the sustained consonant-vowel syllable /m partial partial differential/ at comfortable levels of speech for at least 5 seconds. After nasal decongestant treatment, the second voice sample was collected. Sound spectrum was obtained by the algorithm of fast Fourier transform and the fundamental frequency (F0) was calculated by the method of autocorrelation. Voice low tone to high tone ratio (VLHR) was defined as the division of low frequency power (LFP) into high frequency power (HFP) of the sound power spectrum and was finally expressed in decibels. The cut-off frequency was the product of F0 and square root of (4 x 5). The VLHR after nasal decongestant treatment increased significantly as compared with that before treatment (P < 0.01). VLHR is a new index derived from sound spectral analysis and that may detect the changes in frequency characteristics of voice during treatment for nasal obstruction. The index is quantitative, non-invasive, and potentially useful for basic researches and clinical applications.

Adolescent↗

PubMed2003

Effects of estrogen on gender-related autonomic differences in humans.

Our previous studies demonstrated that premenopausal women have dominant vagal and subordinate sympathetic activity compared with age-matched men. This study was designed to investigate the role of estrogen in gender-related autonomic differences. We evaluated the heart rate variability of four healthy groups: age-matched postmenopausal women without hormone replacement therapy (PM), postmenopausal women on conjugated estrogen replacement therapy (PME), men, and non-age-matched premenopausal women (PreM). Frequency-domain analysis of short-term and stationary R-R intervals was performed to evaluate low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF; 0.15-0.40 Hz), the ratio of LF to HF (LF/HF), and LF in normalized units (LF%). No gender-related autonomic differences existed between the PM and men groups, but they did exist between the PME and men group. Compared with the PreM group, the PM group had a lower HF and higher LF% and LF/HF. Compared with the PM group, the PME group had a higher HF but lower LF% and LF/HF. These results suggest that conjugated estrogen replacement therapy may facilitate vagal and attenuate sympathetic regulation of heart rate in postmenopausal women. In addition, estrogen may play an important role in gender-related autonomic differences.

Adult↗

PubMed2003

Relationship between electroencephalogram slow-wave magnitude and heart rate variability during sleep in rats.

To explore whether depth of sleep is related to changes in autonomic control in rats, continuous power-spectral analysis of electroencephalogram (EEG) and heart rate variability (HRV) was performed in unanesthetized rats during normal daytime sleep. Quiet sleep (QS) was associated with an increase in high-frequency power of HRV (0.6-2.4 Hz, HF) but a decrease in low-frequency power (0.06-0.6 Hz) to HF ratio (LF/HF) compared with awakening. During QS, LF/HF was significantly and negatively correlated with delta power of EEG (0.5-4.0 Hz), whereas mean R-R interval and HF were not. As in humans, cardiac sympathetic regulation in rats is negatively related to the depth of sleep during QS, although vagal regulation is not. Our methodology offers a parallel way of studying the interaction between cerebral cortical and autonomic functions in rats.

Animals↗