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1.
J Am Chem Soc ; 145(48): 25942-25947, 2023 Dec 06.
Article in English | MEDLINE | ID: mdl-37890151

ABSTRACT

We report the seminal experimental isolation and DFT characterization of pristine [5,5] C130-D5h(1) fullertubes. This achievement represents the largest soluble carbon molecule obtained in its pristine form. The [5,5] C130 species is the highest aspect ratio fullertube purified to date and now surpasses the recent gigantic [5,5] C120-D5d(1). In contrast to C90, C100, and C120 fullertubes, the longer C130-D5h has more nanotubular carbons (70) than end-cap fullerenyl atoms (60). Starting from 39,393 possible C130 isolated pentagon rule (IPR) structures and after analyzing polarizability, retention time, and UV-vis spectra, these three layers of data remarkably predict a single candidate isomer and fullertube, [5,5] C130-D5h(1). This structural assignment is augmented by atomic resolution STEM data showing distinctive and tubular "pill-like" structures with diameters and aspect ratios consistent with [5,5] C130-D5h(1) fullertubes. The high selectivity of the aminopropanol reaction with spheroidal fullerenes permits facile separation and removal of fullertubes from soot extracts. Experimental analyses (HPLC retention time, UV-vis, and STEM) were synergistically used (with polarizability and DFT property calculations) to down select and confirm the C130 fullertube structure. Achieving the isolation of a new [5,5] C130-D5h fullertube opens the door to application development and fundamental studies of electron confinement, fluorescence, and metallic character for a fullertube series of molecules with systematic tubular elongation. This [5,5] fullertube family also invites comparative studies with single-walled carbon nanotubes (SWCNTs), nanohorns (SWCNHs), and fullerenes.

2.
Cureus ; 15(3): e36099, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36937123

ABSTRACT

Platelet-rich plasma (PRP), an inexpensive yet powerful treatment modality, is widely used but poorly understood. Three areas of unmet need are the ability to compare results using differing centrifuges and methods; translating a study result into a specific practice; and estimating yield and dosage without the benefit of an in-office hematology analyzer. PRPCalc2 is a set of software tools that facilitates these goals. The app consists of software tools that (1) calculate the appropriate radius for centrifugation, (2) calculate the correct revolutions per minute (RPM) for the centrifuge, (3) calculate the mean yield for the method and its confidence interval, and (4) calculate platelet dosage. Using these tools, a practitioner with any centrifuge can create and validate their own PRP preparation method and then use it to create a standardized PRP.

3.
Cureus ; 14(5): e25081, 2022 May.
Article in English | MEDLINE | ID: mdl-35733469

ABSTRACT

Platelet-rich plasma (PRP) and hypertonic dextrose solutions are commonly used injectates in regenerative medicine, sometimes used simultaneously. The effects of hypertonic dextrose on platelet lysis and activation have not been previously reported. We tested the effects of escalating dextrose concentration on cell counts and cell volume of platelets and red cells in PRP and whole blood (WB). A prompt partial reduction in platelet count occurred with all dextrose admixtures with either PRP or whole blood, consistent with partial lysis. After the first minute, platelet counts remained stable, suggesting a rapid accommodation of residual platelets to extreme (>2000 mOsm) hypertonicity. A 25% or higher dextrose concentration caused a significant increase in mean platelet volume (MPV), which suggests an early phase of platelet activation. Further investigation is warranted to confirm if platelet lysis or activation has occurred and whether additive clinical benefit may result from hypertonic dextrose injection alone or in combination with PRP.

4.
Cureus ; 14(4): e23909, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35411286

ABSTRACT

Despite years of standard treatments, a Marine veteran and former firefighter, disabled due to severe post-traumatic stress disorder (PTSD), worsened over ten weeks while receiving usual care. Bilateral injection of 10 mL of 5% dextrose in water using a 30-gauge needle just under the sternocleidomastoid muscle was performed at weeks 10, 12, 14, 16, and 18. Clinically important improvements were observed by 18 weeks on a 0-10 anxiety rating scale (57%), the PTSD checklist for civilians (41%), EuroQol overall quality of life scale (40%), and the Hospital Anxiety and Depression Scale (28%). Improvements were stable through 22 weeks. He reported symptomatic benefit on anxiety within 20 minutes of injection, suggesting a neurogenic mechanism, potentially related to a therapeutic effect on the nearby sympathetic trunk/superior sympathetic ganglion. Advantages of this procedure over stellate ganglion blockade include its safety (no lidocaine), bilateral treatment option, simplicity, and comfort.

5.
Cureus ; 13(11): e19483, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34912624

ABSTRACT

BACKGROUND: Low back pain (LBP) is common, costly, and disabling. This study assesses a novel and simple LBP evaluation method and its merit in guiding the direction of a self-treatment exercise. METHODS: Randomized open-label intention is used to treat the study. Consecutive patients with LBP ≥ three months and pain ≥ 5/10 were evaluated in a Vancouver clinic with the sacroiliac forward flexion test (SIFFT) by comparing the height of posterior superior iliac spines using a level. Those with asymmetry ≥ 5 mm were offered participation. The assistant, who generated and encrypted the randomization, assigned participants: group 1 learned a two-minute, SIFFT-derived, sacroiliac-leveling exercise (SIFFT-E) as needed for LBP relief; group 2 used a pelvic stabilization belt as needed to prevent LBP, and group 3 continued the usual care. After one month, all participants used SIFFT-E and belt as needed for one month. The identifier number of this article in Clinicaltrials.gov is #NCT03888235. The trial is closed. Our primary outcome measure was the Oswestry disability index (ODI) (decrease) from baseline to one and two months. We also followed SIFFT improvement (decrease). FINDINGS: Of 72 LBP patients, 62 (86%) had ≥ 5 mm asymmetry. From zero to one month, the 21 (one dropout) SIFFT-E participants outperformed the 20 usual care participants for ODI improvement (12.5 ± 14.8 vs. -3.4 ± 14.9 points; mean difference 15.9 [CI 6.7-25.0]; P = 0.002 with number needed to treat (NNT) of 3.0 for ODI improvement ≥ 11). Belt use results were intermediate. At two months, after all the 62 participants used the exercise and belt as needed, combined ODI improvements were clinically significant (12.0 ± 18.4 points), and SIFFT asymmetry was reduced by 8.6 ± 8.6 mm. Five (8%) exercise and 12 (19%) belt wearers experienced mild side effects. INTERPRETATION: Sacroiliac asymmetry appears to be frequent. SIFFT may be clinically useful as an evaluation tool for prescribing a simple self-directed corrective exercise as seen by clinically significant improvements in function and asymmetry.

6.
EClinicalMedicine ; 38: 101008, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34308315

ABSTRACT

Background: Reducing the high patient and economic burden of early readmissions after hospitalisation for heart failure (HF) has become a health policy priority of recent years. Methods: An observational study linking Hospital Episode Statistics to socioeconomic and death data in England (2002-2018). All first hospitalisations with a primary discharge code for HF were identified. Quasi-poisson models were used to investigate trends in 30-day readmissions by age, sex, socioeconomic status and ethnicity. Findings: There were 698,983 HF admissions, median age 81 years [IQR 14].In-hospital deaths reduced by 0.7% per annum (pa), whilst additional deaths at 30-days remained stable at 5%. Age adjusted 30-day readmissions (21% overall), increased by 1.4% pa (95% CI 1.3-1.5). Readmissions for HF (6%) and 'other cardiovascular disease (CVD)' (3%) remained stable, but readmissions for non-CVD causes (12%) increased at a rate of 2.6% (2.4-2.7) pa. Proportions were similar by sex but trends diverged by ethnicity. Black groups experienced an increase in readmissions for HF (1.8% pa, interaction-p 0.03) and South Asian groups had more rapidly increasing readmission rates for non-CVD causes (interaction-p 0.04). Non-CVD readmissions were also more prominent in the least (15%; 15-15) compared to the most affluent group (12%; 12-12). Strongest predictors for HF readmission were Black ethnicity and chronic kidney disease, whilst cardiac procedures were protective. For non-CVD readmissions, strongest predictors were non-CVD comorbidities, whilst cardiologist care was protective. Interpretation: In HF, despite readmission reduction policies, 30-day readmissions have increased, impacting the least affluent and ethnic minority groups the most. Funding: NIHR.

7.
Cureus ; 13(4): e14470, 2021 Apr 13.
Article in English | MEDLINE | ID: mdl-33996329

ABSTRACT

Platelet-rich plasma (PRP) is usually described with respect to its platelet concentration and sometimes the concentration of erythrocytes and leukocytes. In this study, we examined the numbers of leukocyte subtypes in PRPs prepared by five different methods. Single spin PRP methods evaluated resulted in a significant increase in the percentage of lymphocytes and proportional/inverse reduction of the percentage of granulocytes in comparison to those percentages found in whole blood. We propose that the centrifugation process traps the denser granulocytes in the RBC layer more readily than lymphocytes and that this will vary by g force and time. The PRP preparation method may be clinically relevant, because the distribution of leukocytes may affect clinical outcomes.

8.
J Pain Res ; 13: 1957-1968, 2020.
Article in English | MEDLINE | ID: mdl-32801851

ABSTRACT

Nerve hydrodissection (HD), a technique used when treating nerve entrapments, involves the injection of an anesthetic, saline, or 5% dextrose in water to separate the nerve from the surrounding tissue, fascia, or adjacent structures. Animal models suggest the potential for minimal compression to initiate and perpetuate neuropathic pain. Mechanical benefits of HD may relate to release of nervi nervorum or vasa nervorum compression. Pathologic nerves can be identified by examination or ultrasound visualization. The in-plane technique is the predominant and safest method for nerve HD. Five percent dextrose may be favored as the preferred injectate based on preliminary comparative-injectate literature, but additional research is critical. Literature-based hypotheses for a direct ameliorative effect of dextrose HD on neuropathic pain are presented.

9.
Platelets ; 31(5): 661-666, 2020 Jul 03.
Article in English | MEDLINE | ID: mdl-31498027

ABSTRACT

Single-spin methods of preparation of platelet-rich plasma are used widely in private practice, yet they have not been extensively studied and compared. The use of platelet-rich plasma (PRP) by the private practitioner can be facilitated by efficient and predictable PRP preparation. The primary purpose of this study was to study common methods of single-spin PRP preparation to determine their efficiency and variability. Six single-spin methods of PRP production from whole blood were analyzed. The primary measures were mean yield and standard deviation as the quotient of total platelet count in PRP produced divided by total platelet count in whole blood utilized. Each sample was analyzed in triplicate and the results were averaged. Secondary measures included red blood cell count (RBC) and white blood cell count (WBC), concentration ratio, and variable cost per million platelets produced. Sixty-four volunteers provided samples from 30 June 2017 to 30 September 2018. Seventeen to twenty six samples were utilized to assess each method. Yields for the six preparation methods (PMs) varied from 53(±18)% to 72(±13)%. Differences were observed for WBC count (1.8 to 14), Hematocrit (0.8 to 32), platelet concentration (568 to 1062), and variable cost per billion platelets produced ($1.55 to $44.31). All six methods evaluated provided a platelet yield of more than 50%, although two methods were less efficient than the others. Two methods were able to produce leukocyte-poor PRP. Variability was moderate across all methods, suggesting that estimation of platelet yield should be feasible from a baseline platelet count for all methods.


Subject(s)
Blood Platelets/metabolism , Centrifugation/methods , Platelet Count/methods , Platelet-Rich Plasma/metabolism , Humans
10.
Mayo Clin Proc ; 94(5): 820-832, 2019 05.
Article in English | MEDLINE | ID: mdl-30878157

ABSTRACT

OBJECTIVE: To assess the efficacy and longer-term effectiveness of dextrose prolotherapy injections in participants with temporomandibular dysfunction. PATIENTS AND METHODS: A randomized controlled trial with masked allocation was conducted from January 14, 2013, through December 19, 2015. Forty-two participants (with 54 joints) meeting temporomandibular dysfunction criteria were randomized (1:1) to 3 monthly intra-articular injections (20% dextrose/0.2% lidocaine or 0.2% lidocaine) followed by as-needed dextrose/0.2% lidocaine injections through 1 year. Primary and secondary outcome measures included a 0 to 10 Numerical Rating Scale score for facial pain and jaw dysfunction; maximal interincisal opening (MIO) measured in millimeters, percentage of joints with 50% or more change (improvement) in pain and function, and satisfaction. RESULTS: Randomization produced a control group with more female participants (P=.03), longer pain duration (P=.01), and less MIO (P=.01). Upon 3-month analysis, including pertinent covariates, dextrose group participants reported decreased jaw pain (4.3±2.9 points vs 1.8±2.7 points; P=.02), jaw dysfunction (3.5±2.8 points vs 1.0±2.1 points; P=.008), and improved MIO (1.5±4.1 mm vs -1.8±5.1 mm; P=.006). Control group participants received dextrose injections beginning at 3 months. No between-group differences were noted at 12 months; pooled data suggested that jaw pain, jaw function, and MIO improved by 5.2±2.7 points (68%), 4.1±2.8 points (64%), and 2.1±5.5 mm, respectively. Pain and dysfunction improved by at least 50% in 38 of 54 (70%) and 39 of 54 (72%) jaws, respectively. CONCLUSION: Intra-articular dextrose injection (prolotherapy) resulted in substantial improvement in jaw pain, function, and MIO compared with masked control injection at 3 months; clinical improvements endured to 12 months. Satisfaction was high. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01706172.


Subject(s)
Glucose/administration & dosage , Prolotherapy/methods , Temporomandibular Joint Dysfunction Syndrome/drug therapy , Adult , Aged , Cross-Over Studies , Female , Humans , Injections, Intra-Articular , Male , Middle Aged , Single-Blind Method , Treatment Outcome
11.
J Dairy Sci ; 100(6): 4349-4353, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28434726

ABSTRACT

Kefir is a fermented milk product that is a good source of protein and health-promoting bacteria. It has the potential to improve recovery from exercise and the health and well-being of cancer survivors. The purpose of this study was to explore cancer survivor attitudes about and acceptance of a kefir recovery beverage made from cultured milk, whole fruit, natural sweeteners, and other natural ingredients. Kefir was made by inoculating and fermenting milk with kefir grains. The kefir was then mixed with a fruit base and given to cancer survivors (n = 52) following a bout of exercise. Participants evaluated the acceptability of the beverage samples (overall appearance, aroma, taste, mouthfeel, and overall liking) using a 9-point hedonic scale, and they evaluated the smoothness using a 3-category just-about-right scale (not enough, just about right, and too much). They also expressed their physical and psychological feelings about the beverage using a 5-point scale (1 = not at all to 5 = extremely) and indicated their purchase intent using a binomial (yes/no) response. The health benefits of kefir were then explained, and participants sampled a second beverage (the same product), answering the same questions related to overall liking, feeling, and intent to purchase. We used a paired Student's t-test to compare beverage liking and emotion scores before and after participants learned about the health benefits of kefir. Data are presented as mean ± standard deviations. The beverage scored significantly higher for overall liking after the health benefits were explained (6.5 ± 1.8 and 7.0 ± 1.7 out of 9 before and after the explanation of health benefits, respectively). Participants showed a high intent to purchase before they learned about the health benefits (75% of participants indicated an intent to purchase, and 89% after they learned about the health benefits). The beverage received high scores overall and, except for an improvement in overall liking, we observed no significant differences in physical and psychological feelings before and after participants learned that it contained kefir and had potential health benefits. We found the beverage to be acceptable for consumption by cancer survivors, and the majority of participants showed an interest in purchasing for after exercise.


Subject(s)
Attitude , Beverages , Cancer Survivors/psychology , Exercise/physiology , Kefir , Cultured Milk Products , Humans , Smell , Taste
12.
Bull Environ Contam Toxicol ; 98(3): 353-358, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27510992

ABSTRACT

This study reports on the direct reduction of hexavalent chromium [Cr(VI)] by green tea polyphenols, including a green tea solution and pure epigallocatechin gallate (EGCG) solution. A linear trend was observed between the amount of reduced Cr(VI) and the amount of added polyphenols. The green tea solution showed a continued decrease in the observed stoichiometry with increasing pH, from a maximum of 1.4 mol per gallic acid equivalent (GAE) of green tea at pH 2.5, to 0.2 mol/GAE at pH 8.8. The EGCG solution exhibited different behavior, with a maximum stoichiometry of 2 at pH 7 and minimum of 1.6 at pH 4.4 and 8.9. When green tea was used to first react with Fe3+ and form GT-nZVI, the amount of Cr(VI) reduced by a certain volume of GT-nZVI was double compared to green tea, and 6 times as high considering that GT-nZVI only contains 33 % green tea.


Subject(s)
Chromium/chemistry , Chromium/isolation & purification , Iron/chemistry , Polyphenols/chemistry , Tea/chemistry , Catechin/analogs & derivatives , Catechin/chemistry , Environmental Restoration and Remediation/methods , Hydrogen-Ion Concentration , Nanoparticles/chemistry , Solutions/chemistry , Water Pollutants, Chemical
14.
PM R ; 7(11): 1111-1117, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25978942

ABSTRACT

BACKGROUND: Capsaicin specifically activates, and then gradually exhausts, the transient receptor potential vanilloid type 1 (TRPV1) receptor, a key receptor in neuropathic pain. Activation of the TRPV-1 receptor is accompanied by burning pain. A natural substance or medication that can reduce the burning pain resulting from capsaicin application may have therapeutic potential in neuropathic pain. OBJECTIVE: To assess the pain-relieving effects of a mannitol-containing cream in a capsaicin-based pain model. DESIGN: Randomized, placebo-controlled, double-blind clinical trial. SETTING: Outpatient pain clinic. PARTICIPANTS: Twenty-five adults with pain-free lips. METHODS: Capsaicin .075% cream was applied to both halves of each participant's upper lip, inducing pain via stimulation of the transient receptor potential vanilloid 1 (TRPV1, capsaicin) receptor, then removed after 5 minutes or when participants reported a burning pain of 8/10, whichever came first. A cream containing mannitol and the same cream without mannitol (control) were then immediately applied, 1 on each side of the lip, in an allocation-masked manner. OUTCOME MEASURES: Participants self-recorded a numeric rating scale (NRS, 0-10) pain score for each side of the lip per minute for 10 minutes. A t-test was performed to evaluate the pain score change from baseline between each side of the lip at each recording. Area under the curve (AUC) analysis was used to determine the overall difference between groups. RESULTS: Participants reached a capsaicin-induced pain level of 7.8 ± 1.0 points in 3.3 ± 1.6 minutes that was equal on both sides of the lip. Both groups reported progressive diminution of pain over the 10-minute study period. However, participants reported significantly reduced pain scores on the mannitol cream half-lip compared to control at 3 through 10 minutes (P < .05) and in AUC analysis (P < .001). CONCLUSIONS: Mannitol cream reduced self-reported pain scores in a capsaicin pain model more rapidly than a control cream, potentially via a TRPV1 receptor effect.


Subject(s)
Acute Pain/drug therapy , Acute Pain/etiology , Capsaicin , Mannitol/administration & dosage , Sweetening Agents/administration & dosage , Administration, Topical , Adult , Aged , Double-Blind Method , Female , Humans , Lip , Male , Middle Aged , Pain Measurement , Pilot Projects , Skin Cream , Treatment Outcome
15.
Tob Control ; 24(e2): e168-77, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25472733

ABSTRACT

INTRODUCTION: Transnational tobacco companies (TTCs) submitted evidence to the 2012 UK Consultation on standardised packaging (SP) to argue the policy will have detrimental economic impacts and increase illicit tobacco trade. METHODS: A content analysis of the four TTC submissions to the consultation assessed the relevance and quality of evidence TTCs cited to support their arguments. Investigative research was used to determine whether the cited evidence was industry connected. Fisher's exact tests were used to compare the relevance and quality of industry-connected and independent from the industry evidence. The extent to which TTCs disclosed financial conflicts of interest (COI) when citing evidence was examined. RESULTS: We obtained 74 pieces of TTC-cited evidence. The quality of the evidence was poor. TTCs cited no independent, peer-reviewed evidence that supported their arguments. Nearly half of the evidence was industry-connected (47%, 35/74). None of this industry-connected evidence was published in peer-reviewed journals (0/35) and 66% (23/35) of it was opinion only. Industry-connected evidence was of significantly poorer quality than independent evidence (p<0.001). COIs were not disclosed by TTCs in 91% (32/35) of cases. CONCLUSIONS: In the absence of peer-reviewed research to support their arguments, TTCs relied on evidence they commissioned and the opinions of TTC-connected third-parties. Such connections were not disclosed by TTCs when citing this evidence and were time consuming to uncover. In line with Article 5.3 of the Framework Convention on Tobacco Control and broader transparency initiatives, TTCs should be required to disclose their funding of all third-parties and any COIs when citing evidence.


Subject(s)
Commerce/economics , Conflict of Interest , Health Policy , Product Packaging , Smoking/legislation & jurisprudence , Tobacco Industry/ethics , Tobacco Products/economics , Crime , Humans , Internationality , Marketing/economics , Marketing/ethics , Product Packaging/economics , Product Packaging/legislation & jurisprudence , Reference Standards , Tobacco Industry/economics , United Kingdom
16.
J Sports Med Phys Fitness ; 55(10): 1107-13, 2015 Oct.
Article in English | MEDLINE | ID: mdl-24998616

ABSTRACT

AIM: Barefoot running can improve running economy (RE) compared to shod running at low exercise intensities, but data is lacking for the higher intensities typical during many distance running competitions. The influence of barefoot running on the velocity at maximal oxygen uptake (vVO2max) and peak incremental treadmill test velocity (vmax) is unknown. The present study tested the hypotheses that barefoot running would improve RE, vVO2max and vmax relative to shod running. METHODS: Using a balanced within-subject repeated measures design, eight male runners (aged 23.1±4.5 years, height 1.80±0.06 m, mass 73.8±11.5 kg, VO2max 4.08±0.39 L·min(-1)) completed a familiarization followed by one barefoot and one shod treadmill running trial, 2-14 days apart. Trial sessions consisted of a 5 minute warm-up, 5 minute rest, followed by 4×4 minute stages, at speeds corresponding to ~67, 75, 84 and 91% shod VO2max respectively, separated by a 1 minute rest. After the 4th stage treadmill speed was incremented by 0.1 km·h(-1) every 15 s until participants reached volitional exhaustion. RESULTS: RE was improved by 4.4±7.0% across intensities in the barefoot condition (P=0.040). The improvement in RE was related to removed shoe mass (r2=0.80, P=0.003) with an intercept at 0% improvement for RE at 0.520 kg total shoe mass. Both vVO2max (by 4.5±5.0%, P=0.048) and vmax (by 3.9±4.0%, P=0.030) also improved but VO2max was unchanged (p=0.747). CONCLUSION: Barefoot running improves RE at high exercise intensities and increases vVO2max and vmax, but further research is required to clarify the influence of very light shoe weights on RE.


Subject(s)
Athletic Performance/physiology , Exercise Test , Heart Rate/physiology , Oxygen Consumption/physiology , Running , Shoes , Adaptation, Physiological , Adult , Analysis of Variance , Fatigue , Homeostasis , Humans , Male , Rest , Running/physiology
17.
Science ; 346(6207): 1255724, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25324396

ABSTRACT

The physical processes causing energy exchange between the Sun's hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to 60 seconds) of intensity and velocity on small spatial scales (≲500 kilometers) at the footpoints of hot and dynamic coronal loops. The observations are consistent with numerical simulations of heating by beams of nonthermal electrons, which are generated in small impulsive (≲30 seconds) heating events called "coronal nanoflares." The accelerated electrons deposit a sizable fraction of their energy (≲10(25) erg) in the chromosphere and TR. Our analysis provides tight constraints on the properties of such electron beams and new diagnostics for their presence in the nonflaring corona.

18.
Science ; 346(6207): 1255726, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25324397

ABSTRACT

The solar atmosphere was traditionally represented with a simple one-dimensional model. Over the past few decades, this paradigm shifted for the chromosphere and corona that constitute the outer atmosphere, which is now considered a dynamic structured envelope. Recent observations by the Interface Region Imaging Spectrograph (IRIS) reveal that it is difficult to determine what is up and down, even in the cool 6000-kelvin photosphere just above the solar surface: This region hosts pockets of hot plasma transiently heated to almost 100,000 kelvin. The energy to heat and accelerate the plasma requires a considerable fraction of the energy from flares, the largest solar disruptions. These IRIS observations not only confirm that the photosphere is more complex than conventionally thought, but also provide insight into the energy conversion in the process of magnetic reconnection.

19.
Science ; 346(6207): 1255711, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25324395

ABSTRACT

As the interface between the Sun's photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow bright network lanes of this interface region. These jets have lifetimes of 20 to 80 seconds and widths of ≤300 kilometers. They originate from small-scale bright regions, often preceded by footpoint brightenings and accompanied by transverse waves with amplitudes of ~20 kilometers per second. Many jets reach temperatures of at least ~10(5) kelvin and constitute an important element of the transition region structures. They are likely an intermittent but persistent source of mass and energy for the solar wind.

20.
Science ; 346(6207): 1255757, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25324399

ABSTRACT

The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long-standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the magnetically controlled structure of these regions. The high spatial and temporal resolution observations with the Interface Region Imaging Spectrograph (IRIS) at the solar limb reveal a plethora of short, low-lying loops or loop segments at transition-region temperatures that vary rapidly, on the time scales of minutes. We argue that the existence of these loops solves a long-standing observational mystery. At the same time, based on comparison with numerical models, this detection sheds light on a critical piece of the coronal heating puzzle.

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