Flare Levels Research Articles

P512 Safety of reduced clinical monitoring in patients with stable Inflammatory Bowel Disease on maintenance thiopurine therapy

Abstract Background Thiopurine-treated inflammatory bowel disease (IBD) patients are monitored every 3 to 4 months with outpatient visits and laboratory assessments to evaluate disease activity and safety of therapy. However, the risk of thiopurine-related adverse events decreases after the initiation phase. The aim of this study was to assess the safety of reduced clinical monitoring in steroid-free quiescent IBD patients on stable maintenance thiopurine monotherapy. Methods This single-centre prospective cohort study evaluated a reduced monitoring strategy that involved 6-monthly laboratory assessment combined with alternating outpatient and phone appointments, during 104 weeks. We enrolled IBD patients who were in steroid-free remission > 6 months on thiopurine monotherapy including azathioprine, 6-mercaptopurine or tioguanine. The primary outcome was thiopurine-related adverse events (AE) requiring change or discontinuation of thiopurine therapy after 104 weeks of follow-up. Secondary outcomes were assessed at week 52 and included other thiopurine-related AEs and laboratory abnormalities. Results We included 85 patients (42 years median age, 61.2% Crohn’s disease, 62% female) with a median disease duration of 12.5 years. At baseline, 47 patients were treated with azathioprine (55.3%), 25 with 6-mercaptopurine (29.4%) and 13 with tioguanine (15.3%) for a median duration of 6.7 years. During 104 weeks of follow-up, thiopurine therapy was ceased in two patients because of multiple infections (n=1) and gastrointestinal complaints (n=1). Other reasons for thiopurine cessation (n=37) were stable remission (n=26), patient preferences (n=9) and high 6-TGN levels (n=2). In total, 20 patients underwent thiopurine dose adjustments due to high metabolite levels (n=9), remission (n=3), disease flare (n=3), patient preferences (n=3), and low metabolite levels (n=2). At 52 weeks, 27 laboratory abnormalities were observed, yet none required therapy adjustments. In 13 patients (15.3%) myelotoxicity was detected, including mild leukopenia (n=11), mild and moderate thrombopenia (n=2). In 16.5%, hepatoxicity was observed (n=14) including mild (n=9) and moderate (n=1) elevated aspartate aminotransferase and mild elevated alkaline phosphatase (n=4). Conclusion A reduced monitoring strategy appeared relatively safe in a strictly selected cohort of stable thiopurine-treated IBD patients. Overall, two patients had to cease thiopurine therapy due to thiopurine-related AEs independent of monitoring frequency. No laboratory abnormalities required therapy adjustments and 57.1% of patients continued therapy throughout 104 weeks of follow-up. This strategy may contribute to safe reduction of time and health care costs for both IBD patients and physicians in daily IBD practice.

Image processing methods for Rayleigh scattering measurements of diesel spray mixing at high repetition rate

This work describes the diagnostic implementation and image processing methods to quantitatively measure diesel spray mixing injected into a high-pressure, high-temperature environment. We used a high-repetition-rate pulse-burst laser developed in-house, a high-speed CMOS camera, and optimized the optical configuration to capture Rayleigh scattering images of the vaporized fuel jets inside a constant volume chamber. The experimental installation was modified to reduce reflections and flare levels to maximize the images’ signal-to-noise ratios by anti-reflection coatings on windows and surfaces, as well as series of optical baffles. Because of the specificities of the high-speed system, several image processing techniques had to be developed and implemented to provide quantitative fuel concentration measurements. These methods involve various correction procedures such as camera linearity, laser intensity fluctuation, dynamic background flare, as well as beam-steering effects. Image inpainting was also applied to correct the Rayleigh scattering signal from large scatterers (e.g. particulates). The experiments demonstrate that applying planar laser Rayleigh scattering at high repetition rate to quantitatively resolve the mixing of fuel and ambient gases in diesel jets is challenging, but possible. The thorough analysis of the experimental uncertainty and comparisons to past data prove that such measurements can be accurate, whilst providing valuable information about the mixing processes of high-pressure diesel jets.

The Correlation of Inflammation and Microvascular Changes with Diabetic Retinal Neurodegeneration

ABSTRACT Purpose: To evaluate the effect of aqueous flare intensity as a measurement of inflammation and microvascular changes on retinal neurodegeneration in diabetic eyes. Materials and Methods: In cross-sectional study diabetic patients were assigned into 2 groups according to the presence of retinopathy: patients with nonproliferative diabetic retinopathy (group 1) and diabetic patients without clinically overt retinopathy (group 2). As a control group (group 3), age-matched healthy controls were included in the study. All subjects underwent visual acuity measurement, slit-lamp examination, ophthalmoscopy, spectral-domain optic coherence tomography (SD-OCT), optic coherence tomography angiography (OCTA), and laser flare-cell meter (LFCM). Results: The study enrolled 99 eyes of 99 patients in group 1; 99 eyes of 99 patients in group 2, and 50 eyes of 50 age-matched healthy controls in group 3. The eyes in group 1 had higher flare intensity, decreased ganglion cell layer (GCL) thickness, enlarged foveal avascular zone (FAZ) area, and enlarged capillary non-flow area compared to those in group 2 (p < .005). In group 1, decreased GCL thickness was statistically significantly correlated with increased aqueous flare intensity, enlarged FAZ area, and enlarged capillary non-flow area (p < .005). Conclusion: The results demonstrated a correlation of the retinal neurodegeneration with the aqueous flare levels and macular ischemia indices in the early stages of diabetic retinopathy. This finding supports the role of inflammation in the pathogenesis of diabetic retinal neuropathy.

Analysis of Global Ionospheric Response to Solar Flares Based on Total Electron Content and Very Low Frequency Signals

The response of the global ionosphere to solar flares is an important topic in the field of space weather. The global ionospheric response to solar flares is comprehensively analyzed from the perspectives of total electron content (TEC) and very low frequency (VLF) signals by using solar flare data on the eruption days of X-class flares from 2006 to 2019, including flare level, flare duration, geographical location, and local time. In addition, the relationship between X-ray flux and VLF phase variation is studied through correlation analysis. The concepts of disturbance intensity (DI) and disturbance angle are defined, and a DI evaluation model is established to help detect the difference in sensitivity to solar flares between TEC and VLF signals. Results show the following. (1) The higher the flare level and the longer the duration, the greater the disturbance to the ionosphere. Simultaneously, a phenomenon exists in which the disturbance caused by low-level and long-lasting flares is greater than that caused by high-level flares. (2) VLF phase variation and flare level exhibit a good correlation, and they are also closely related to geographical location and local time. The disturbance degree of a station facing the sun is more evident than that of a station facing away from the sun. The TEC disturbance of stations in the morning (local time) is more obvious than that in the afternoon, and disturbance increases along the direction of Earth’s rotation. (3) When DI is at the same level, the lowest flare level that causes TEC response is higher than the lowest flare level that causes VLF signal response. The disturbance angle of TEC is unevenly distributed within the interval [0°, 90°], and that of VLF signals is more than 85°. The sensitivity of VLF signals to flare response is considerably higher than that of TEC, and the difference between the two even stride across DI level.

High-latitude crochet: solar-flare-induced magnetic disturbance independent from low-latitude crochet

Abstract. A solar-flare-induced, high-latitude (peak at 70–75∘ geographic latitude – GGlat) ionospheric current system was studied. Right after the X9.3 flare on 6 September 2017, magnetic stations at 68–77∘ GGlat near local noon detected northward geomagnetic deviations (ΔB) for more than 3 h, with peak amplitudes of &gt;200 nT without any accompanying substorm activities. From its location, this solar flare effect, or crochet, is different from previously studied ones, namely, the subsolar crochet (seen at lower latitudes), auroral crochet (pre-requires auroral electrojet in sunlight), or cusp crochet (seen only in the cusp). The new crochet is much more intense and longer in duration than the subsolar crochet. The long duration matches with the period of high solar X-ray flux (more than M3-class flare level). Unlike the cusp crochet, the interplanetary magnetic field (IMF) BY is not the driver, with the BY values of only 0–1 nT out of a 3 nT total field. The equivalent ionospheric current flows eastward in a limited latitude range but extended at least 8 h in local time (LT), forming a zonal current region equatorward of the polar cap on the geomagnetic closed region. EISCAT radar measurements, which were conducted over the same region as the most intense ΔB, show enhancements of electron density (and hence of ion-neutral density ratio) at these altitudes (∼100 km) at which strong background ion convection (&gt;100 m s−1) pre-existed in the direction of tidal-driven diurnal solar quiet (Sq0) flow. Therefore, this new zonal current can be related to this Sq0-like convection and the electron density enhancement, for example, by descending the E-region height. However, we have not found why the new crochet is found in a limited latitudinal range, and therefore, the mechanism is still unclear compared to the subsolar crochet that is maintained by a transient redistribution of the electron density. The signature is sometimes seen in the auroral electrojet (AE = AU − AL) index. A quick survey for X-class flares during solar cycle 23 and 24 shows clear increases in AU for about half the &gt; X2 flares during non-substorm time, despite the unfavourable latitudinal coverage of the AE stations for detecting this new crochet. Although some of these AU increases could be the auroral crochet signature, the high-latitude crochet can be a rather common feature for X flares. We found a new type of the solar flare effect on the dayside ionospheric current at high latitudes but equatorward of the cusp during quiet periods. The effect is also seen in the AU index for nearly half of the &gt; X2-class solar flares. A case study suggests that the new crochet is related to the Sq0 (tidal-driven part) current.

Disruption of blood-aqueous barrier in dry eye disease

PurposeTo evaluate level of flare in aqueous humor of dry eye disease (DED) and compare it with normal controls. MethodsIn this cross-sectional study, we compared the anterior chamber flare between 28 patients with DED (the DED group) and 27 normal age- and gender-matched controls (the control group). DED group was divided in Sjӧgren's syndrome dry eye (SDE, n = 10) and non- Sjӧgren's syndrome dry eye (non-SDE, n = 18) groups. ResultsThis study enrolled 55 participants including 28 patients with DED and 27 normal controls. The mean age was 53.4 ± 14.7 years in the DED group and 48.5 ± 14.7 years in the control group (P = 0.086). Mean flare was significantly higher in DED group (12.1 ± 10.2 ph/ms, range 2.7–68.3) compared to the control group (5.0 ± 3.9 ph/ms, range 1.30–30.0, P < 0.001). There was no statistically significant difference in the flare intensity between the Sjӧgren syndrome dry eye (SDE) group (14.5 ± 14.4 ph/ms) and the non-Sjӧgren dry eye (non-SDE) group (10.8 ± 6.9 ph/ms, P = 0.330). A significant correlation was observed between the flare intensity and the ocular surface staining in the SDE group (r = 0.62, P = 0.018). ConclusionThere is a significant increase in aqueous humor flare in patients with DED. Such finding, which is a marker of disruption of blood-aqueous barrier, demonstrates deeper tissue involvement than ocular surface in these patients.

Aqueous Flare and Progression of Visual Field Loss in Patients With Retinitis Pigmentosa.

PurposeTo investigate the association between aqueous flare and progression of visual field loss using the Humphrey Field Analyzer in patients with retinitis pigmentosa (RP).MethodsWe examined a total of 101 eyes of 101 patients who were diagnosed with typical RP. Sixty-one percent of the patients were female, and the mean age of the total group was 47.4 years. Aqueous flare, visual field (by an Humphrey Field Analyzer, the central 10-2 SITA-Standard program), and optical coherence tomography measurements were obtained for all patients. The slope, which was derived from serial values of mean deviation, macular sensitivity, or foveal sensitivity for each eye with univariate linear regression, was used for analysis.ResultsAqueous flare values were significantly correlated with the mean deviation slope (r = −0.20, P = 0.046), macular sensitivity slope (r = −0.28, P = 0.005) and foveal sensitivity slope (r = −0.20, P = 0.047). The values of the retinal sensitivity slope significantly decreased as the aqueous flare level increased (all P < 0.05). These associations remained unchanged after adjustment for age, sex, and posterior subcapsular cataract, and epiretinal membrane.ConclusionsElevation of aqueous flare is a risk factor for the decline of central visual function in RP. Aqueous flare may be a useful marker for disease progression in RP.

Evaluation of emulsified silicone oil with spectral domain-optical coherence tomography and fluorescein angiography.

To report emulsified particles and related complications after removal of silicone oil (SO) by spectral domain-optical coherence tomography (SD-OCT) and fluorescein angiography (FA). A prospective, single-center investigation was performed using SD-OCT, FA and flare cell photometry measurements to evaluate in a cohort of eyes with emulsified silicone particles after removal of long-term SO tamponade. Nineteen eyes of the 19 patients with emulsified silicone particles detected in ophthalmoscopic exam were included in the study: 13 (68%) were male, and 6 (31.6%) were female, and their mean age was 52.75 ± 16.06years. Preoperative diagnoses were rhegmatogenous retinal detachment in all eyes. The mean duration of the silicone oil's presence in the eye was found as 12.63 ± 4.87 (7-26) months. SD-OCT examination postoperatively showed small, round and hyper-reflective structures compatible with emulsified silicone particles on preretinal surface in 7 (36.8%) eyes, intraretinally in 6 (31.6%) eyes and in the vitreous in 12 (63%) eyes. FA imaging demonstrated pearl-like hyper-fluorescence at early and late phases on the large blood vessels in 9 (47.4%) eyes. Late phase hyper-fluorescence due to leakage on the macula was observed in 17 (89.5%) eyes. Diffuse peripheral leakage and hyper-fluorescence was detected in 11 (57.9%) eyes. Flare levels were higher in eyes with emulsified SO compared to unaffected fellow eyes (p < 0.05). Emulsified silicone particles that remain in the eye may lead to retinal complications and inflammation in addition to their known complications such as keratopathy and glaucoma. The particles that lead to inflammation and presence of inflammation may be examined by imaging methods such as SD-OCT and FA. Removing the SO before emulsification would be suitable for avoiding such complications.

Role of Inflammation in Retinal Microcirculation in Diabetic Eyes: Correlation between Aqueous Flare and Microvascular Findings

Purpose: To investigate the correlation between aqueous flare and macular microvascular status assessed by optic coherence tomography angiography (OCTA) in diabetes mellitus. Methods: A cross-sectional study was conducted on 52 diabetic patients with nonproliferative retinopathy, 44 diabetic patients without retinopathy, and 20 nondiabetic age-matched controls. Spectral domain OCT, OCTA, and laser flare-cell meter were performed. Results: Compared to eyes without retinopathy, eyes with retinopathy had higher flare intensity (p = 0.024), enlarged capillary nonperfusion area (p < 0.001), and enlarged foveal avascular zone (p < 0.001). There was a significant correlation between flare intensity and capillary nonperfusion areas (p < 0.001, r = 0.511) and superficial capillary density (p = 0.005, r = –0.388) in diabetic eyes with retinopathy. Conclusion: The results demonstrated a positive correlation between aqueous flare levels, an indicator of intraocular inflammation, and microvascular damage demonstrated by OCTA in the early stages of diabetic retinopathy (DR). This finding supports the role of inflammation in the pathogenesis of DR.

Blood-aqueous barrier deterioration following retained metallic corneal foreign body: A laser flare photometric study.

This study aims to use laser flare photometry to evaluate flare changes in patients following corneal damage from a metallic foreign body (FB). Foreign body injured eyes and the healthy fellow eyes of 54 consecutive patients were studied in this comparative, observational, cross-sectional study. Flare levels were analyzed according to demographics, history of previous exposures, foreign body location, and foreign body penetration into the injured cornea. The mean flare value was significantly higher for the eyes with corneal foreign body injury compared to the fellow-control eyes (11.35±14.17 ph/ms and 6.30±3.81 ph/ms, respectively) (p=0.014). The mean flare values were significantly lower in eyes with a history of more than one previous corneal foreign body removal flare values than in other eyes (p=0.029). Flare is increased by corneal foreign body exposure. However, eyes that experience multiple previous corneal foreign body exposures may show relatively low flare, probably due to corneal desensitization.

New Methods for Control System Signal Sampling in Neural Networks of Power Facilities

The authors of the paper emphasize that when the Nyquist-Shannon sampling theorem is used in practice, there arise several problems, which can be explained only through the use of new methodologies and mathematical models. The review of the researchers' works, as well as the authors' own practical research in the course of processing the statistical sample, which is described by a wave-like sine-cosine function, leads to the conclusion that it is necessary to take into account optimization criteria for high-tech processes and innovative indicators of building functions for the statistical sample, for example, when signals are transmitted and sampled using neural networks at production facilities. In the practice of economic calculations, for example, when making a graphic presentation of trend lines based on the functions built subject to the sampling conditions by the Nyquist theorem, the authors propose to use new methods for approximating piece linear functions, which allow for achieving a smaller error as compared to standard calculation methods. The work resulted in the creation of a neural network regulation algorithm, which will be trained based on the collected data and adapted to a specific type of a boiler unit. Besides, it was established that the task of neural network algorithms in the program is to find the optimal value of the weight coefficient for each argument of the resulting function to obtain the maximum number of predictions of the flare level and the particle burn-up time, which are consistent with reality. The use of these methods for the first time made it possible to significantly reduce the error, which is confirmed not only by calculations, but also by experimental data.

Anterior chamber aqueous flare is not a predictor for surgical closure of full-thickness idiopathic macular holes

To investigate the predictive value of preoperative anterior chamber aqueous flare levels measured by laser flare photometry for surgical success of idiopathic macular holes in addition to preoperative anatomic characteristics. Records of 105 consecutive eyes with full-thickness idiopathic macular holes which underwent pars plana vitrectomy with internal limiting membrane peeling and sulfur hexafluoride 20% (SF620%) endotamponade were reviewed retrospectively. All patients underwent preoperative measurements of anterior chamber aqueous flare and anatomical idiopathic macular hole characteristics evaluated by optical coherence tomography: macular hole inner opening diameter, macular hole minimum linear diameter, macular hole base diameter, and macular hole height. Best-corrected visual acuity results were recorded pre- and postoperatively. In 17 (16.2%) of 105 eyes primary closure of idiopathic macular hole failed, whereas in 88 eyes (83.8%) closure was achieved. Between both groups, preoperative macular hole minimum linear diameter (p = 0.001) and macular hole inner opening diameter (p = 0.006) were statistically different. Failure rates were significantly lower in eyes with macular hole minimum linear diameter < 400 µm (7.4% vs 32.4%; p = 0.013) and preoperative macular hole minimum linear diameter showed moderate correlation with pre- and postoperative best-corrected visual acuity results (r = 0.512; p < 0.001; r = 0.612; p < 0.001). Mean anterior chamber aqueous flare of 11.5 ± 9.9 pc/ms in eyes with anatomical closure and 11.8 ± 6.4 pc/ms in unclosed cases was comparable (p = 0.28) and did not correlate with anatomical or functional results. Eyes with idiopathic macular hole ⩾ 400 µm in size have a significantly higher failure rate following standardized pars plana vitrectomy with internal limiting membrane peeling and SF620% endotamponade. Preoperative macular hole minimum linear diameter and macular hole inner opening diameter seem to be associated with surgical outcome in idiopathic macular hole, whereas anterior chamber aqueous flare level does not provide additional predictive value.

A-type stars in the Canada–France Imaging Survey – II. Tracing the height of the disc at large distances with Blue Stragglers

We present the kinematics of Blue Straggler (BS) stars identified in the Canada-France-Imaging-Survey (CFIS), covering 4000 deg$^2$ on the sky in the $u$-band. The BS sample, characterised through CFIS and Pan-STARRS photometry, has been kinematically decomposed into putative halo and disc populations after cross-matching with Gaia astrometry and SDSS/SEGUE/LAMOST spectroscopy. This decomposition clearly reveals the strong flaring of the outer Milky Way disc. In particular, we show that we can detect this flaring up to a vertical height of $|Z| \simeq 8$ kpc at a Galactocentric distance of $R\sim $27 kpc. While some small level of flaring is expected for extended discs built up by radial migration, we demonstrate that this observed very strong flaring of the Milky Way disc is more likely consistent with it being dynamically heated by the repeated passage of the Sagittarius dwarf spheroidal galaxy through the midplane.

Changes in aqueous oxidative stress, prostaglandins, and cytokines: Comparisons of low-energy femtosecond laser–assisted cataract surgery versus conventional phacoemulsification

To compare the aqueous oxidative stress, prostaglandin E2 (PGE2), and cytokine levels after low-energy femtosecond laser-assisted cataract surgery versus conventional phacoemulsification, and to evaluate the effect of a nonsteroidal antiinflammatory drug (NSAID) on the aqueous profiles. Singapore National Eye Center, Singapore. Randomized controlled trial. Thirty-five patients were randomized to receive conventional phacoemulsification in one eye and femtosecond laser-assisted cataract surgery in the fellow eye. Another matched prospective cohort of 35 patients was included to receive femtosecond laser-assisted cataract surgery with a preoperative NSAID. Aqueous humor was collected after the laser was used or at the beginning of surgery (conventional phacoemulsification), and at the end of phacoemulsification. The levels of aqueous malondialdehyde (MDA), PGE2, and cytokines, chemokines, and growth factors were analyzed. The postoperative aqueous flare levels were evaluated. Compared with the conventional group, the femtosecond-assisted group had a significantly higher PGE2 (P=.01) and interleukin-1 receptor antagonist levels (P=0.04). The preoperative NSAID significantly reduced the PGE2 surge (P=.002) and the meanreduction in pupil diameter (P=.02). The MDA concentrations before phacoemulsification were 0.24μmol/L ± 0.18 (SD), 0.51±0.41μmol/L and 0.59±0.52μmol/L for the conventional, femtosecond-assisted, and femtosecond-assisted NSAID groups, respectively (P=.42). After phacoemulsification, the PGE2 and MDA levels increased in allgroups. The MDA induction was significantly correlated with the phacoemulsification time (P=.002). The postoperative flare was insignificantly higher in the femtosecond-assisted group than the conventional group. Compared with conventional phacoemulsification, the femtosecond laser-assisted cataract surgery performed with the Femto LDV Z8 laser platform induced a significantly higher PGE2 level. The MDA and postoperative aqueous flare level were insignificantly higher. The preoperative NSAID reduced the PGE2 surge and occurrence of intraoperative miosis. The oxidative stress induced during phacoemulsification was strongly correlated with phacoemulsification time.

Responses of the D region ionosphere to solar flares revealed by MF radar measurements

Electron density (Ne) and effective reflection height (H', where the electron density reaches its peak value) in the D region observed by medium frequency (MF) radar at Kunming (25.6°N, 103.8°E) were utilized to quantitatively study the ionospheric response to solar flares. It was found that the H' and Ne had profound responses to solar flares. The results showed a sharp decrease in the H' from 76 to 80 km during the non-flare period to nearly 58 km with flares, and a sudden increase in the Ne from below 4×108 m3 in non-flare period to 1.8×109 m3 during 13 M-level flares. The behavior of Ne was strongly and positively correlated with the variation of the X-ray flux, with the largest coefficient being 0.93, while the changes of H' exhibited a strongly negative correlation of −0.96 with that of the X-ray flux. Moreover, variations of H' and ΔNe depended on not only the flare level, but also upon the onset time and duration of flare.

Quantitative Assessment of Aqueous Flare After Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Dystrophy.

To assess aqueous flare as a measure of subclinical inflammation after Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy. In this prospective cross-sectional and longitudinal case series at a tertiary referral center, 173 DMEK eyes of 169 patients and 19 age-matched healthy control eyes were included. Aqueous flare [photon count per millisecond (ph/ms)] was assessed by laser flare photometry at 1 day, 1 week, and 1 month after DMEK in group I (evaluation of postsurgical blood-aqueous barrier recovery; n = 25) and on average 28 (±19) months (range, 3-86 months) after DMEK in group II (evaluation of long-term inflammation; n = 148). In group I, flare levels decreased from 1 day to 1 week [25.1 (±9.1) ph/ms vs. 13.4 (±4.8) ph/ms; P = 0.003] and remained stable up to 1 month after DMEK [12.1 (±3.2) ph/ms; P = 0.387]. However, average flare at 1 month was higher than that in healthy controls (P < 0.001). The long-term flare value after DMEK (group II) was 9.6 (±4.2) ph/ms and was higher in eyes associated with allograft rejection (n = 6) versus those without rejection [16.7 (±7.8) ph/ms vs. 9.3 (±3.8) ph/ms, respectively, P < 0.001]. All eyes associated with rejection had flare values above 10 ph/ms. Aqueous flare after DMEK quickly decreased within the first postoperative month, indicating fast recovery of the blood-aqueous barrier. Long-term flare levels were higher in eyes associated with rejection, suggesting persistent subclinical inflammation. A flare level above 10 ph/ms may be used as a threshold for identifying eyes associated with or at risk of allograft rejection after DMEK.

Associated Petroleum Gas: Problems, Prospects, Ways to Increase Its Effective Use

The purpose of the study is to analyze the efficiency of using associated petroleum gas (APG) and to identify the main problems, prospects and ways to increase the efficiency of its use. The article presents the results of studying the current state policy and national interests in the field of its rational use. The authors carried out an analysis of the current state of the oil and gas market at the international and regional level, as a result of which the main spectrum of problems of APG effective use was identified. A scheme was proposed which regulates the interaction between the APG market participants and is aimed at increasing the level of APG beneficial use in Russia. The authors’ research will make it possible to determine that the most significant factors that ensure a high level of APG flaring in Russia are as follows: the shortage of APG processing capacity, the restriction of oil companies’ access to the Unified Gas Supply System, the gaps in the current legal and regulatory framework, the absence of a single mechanism for the selection of projects on utilizing APG in a particular field/group of fields, as well as pricing in the oil and gas market. The findings are of practical value for scholars in the field of technology management, and for large industrial complexes.

Risk Factors for Posterior Subcapsular Cataract in Retinitis Pigmentosa.

Posterior subcapsular cataract (PSC) is a frequent complication in patients with retinitis pigmentosa (RP). The risk factors for PSC formation in RP are largely unknown. The purpose of this study was to investigate the risk factors for PSC. We retrospectively studied a total of 322 eyes of 173 patients who were diagnosed with typical RP. We considered the following possible risk factors for PSC: age, sex, hypertension, diabetes mellitus, high myopia, asthma, history of steroid intake, and aqueous flare. Aqueous flare values were measured consecutively in 2012 and 2013 using a laser flare cell meter. The lens including PSC was examined with a slit lamp after dilation with tropicamide 1% and phenylephrine 2.5%. The geometric mean values of aqueous flare and mean values of visual acuity were significantly higher for the RP patients with PSC compared to those without PSC (P = 0.0003, P = 0.0004, respectively). When the aqueous flare values were assessed continuously, each 1-log-transformed increase in flare levels was associated with an elevation of the likelihood of having PSC after multivariable adjustment (odds ratio: 1.71; 95% confidence interval: 1.05-2.77). There were no significant associations of the other possible risk factors with PSC. Our analysis demonstrated that elevated aqueous flare is a significant risk factor for PSC formation. This result might provide insights into the association of inflammation and the pathogenesis of PSC formation in RP.

Systemic vasculitis and the eye.

The primary systemic vasculitides represent a spectrum of rare but life-threatening conditions that may also affect the eye in various forms. This article reviews recently published data on ocular manifestations of systemic vasculitis. Early diagnosis and timely treatment has led to better visual outcomes in giant cell arteritis (GCA). Gene expression from orbital tissues could distinguish granulomatosis with polyangiitis (GPA) from sarcoidosis and Graves disease, but not from idiopathic orbital inflammation. Rituximab was an effective therapeutic option in ocular GPA. An ocular attack severity scoring system, flare levels, fluorescein angiography and optical coherence tomography parameters have been suggested as predictors of visual prognosis in Behçet disease. Efficacy of tumor necrosis factor-alpha inhibitors, interferon α and anti-interleukin-1 agents was shown in noncontrolled studies of ocular Behçet disease. Widely used fast-track pathway care as well as ocular imaging to detect subclinical involvement may enable earlier diagnosis of GCA and prevention of permanent visual loss. Orbital inflammation may not remain idiopathic with advances in gene expression profiling of orbital tissues. With an increased availability and the use of biologic agents, visual prognosis will improve in patients with severe ocular complications of systemic vasculitides.

Life cycle greenhouse gas emissions and freshwater consumption associated with Bakken tight oil

In recent years, hydraulic fracturing and horizontal drilling have been applied to extract crude oil from tight reservoirs, including the Bakken formation. There is growing interest in understanding the greenhouse gas (GHG) emissions associated with the development of tight oil. We conducted a life cycle assessment of Bakken crude using data from operations throughout the supply chain, including drilling and completion, refining, and use of refined products. If associated gas is gathered throughout the Bakken well life cycle, then the well to wheel GHG emissions are estimated to be 89 g CO2eq/MJ (80% CI, 87-94) of Bakken-derived gasoline and 90 g CO2eq/MJ (80% CI, 88-94) of diesel. If associated gas is flared for the first 12 mo of production, then life cycle GHG emissions increase by 5% on average. Regardless of the level of flaring, the Bakken life cycle GHG emissions are comparable to those of other crudes refined in the United States because flaring GHG emissions are largely offset at the refinery due to the physical properties of this tight oil. We also assessed the life cycle freshwater consumptions of Bakken-derived gasoline and diesel to be 1.14 (80% CI, 0.67-2.15) and 1.22 barrel/barrel (80% CI, 0.71-2.29), respectively, 13% of which is associated with hydraulic fracturing.