The authors develop a numerical model to elucidate time-distributed processes controlling sediment carbon fate in phreatic karst. Sediment carbon processes simulated in the new numerical model include in conduit erosion and deposition, sediment carbon transport, surficial fine grained laminae evolution, carbon pool mixing, microbial oxidation, and the understudied process of sediment carbon exchange during equilibrium transport. The authors perform a model evaluation procedure that includes generalized likelihood uncertainty estimation to quantify uncertainty of the model results. Modeling results suggest that phreatic karst conduits sustain sediment transport activity long after surface storm events cease. The sustained sediment transport has the potential to shift the baseflow sediment yield of the phreatic karst to be on par with stormflow sediment yield. The sustained activity is suggested to promote the exchange of sediment carbon between the water column and subsurface karst deposits during equilibrium sediment transport conditions. In turn, the sediment carbon exchange impacts the mixing of new and old carbon pools and the flux of carbon from phreatic karst. Integrated numerical model results from this study support the concept that phreatic karst act as a biologically active conveyor of sediment carbon that temporarily stores sediment, turns over carbon at higher rates than surface streams, and recharges degraded carbon back to the fluvial system. The numerical modeling method adopted in this paper shows the efficacy of coupling carbon isotope fingerprinting with water quality modeling to study sediment carbon in phreatic karst. (C) 2017 Elsevier B.V. All rights reserved.

Recent research has paid increased attention to quantifying the fate of carbon pools within fluvial networks, but few, if any, studies consider the fate of sediment organic carbon in fluviokarst systems despite that karst landscapes cover 12% of the earth's land surface. The authors develop a conceptual model of sediment carbon fate in karst terrain with specific emphasis upon phreatic karst conduits, i.e., those located below the groundwater table that have the potential to trap surface-derived sediment and turnover carbon. To assist with their conceptual model development, the authors study a phreatic system and apply a mixture of methods traditional and novel to karst studies, including electrical resistivity imaging, well drilling, instantaneous velocimetry, dye tracing, stage recording, discrete and continuous sediment and water quality sampling, and elemental and stable carbon isotope fingerprinting.Results show that the sediment transport carrying capacity of the phreatic karst water is orders of magnitude less than surface streams during storm-activated periods promoting deposition of fine sediments in the phreatic karst. However, the sediment transport carrying capacity is sustained long after the hydrologic event has ended leading to sediment resuspension and prolonged transport. The surficial fine grained laminae occurs in the subsurface karst system; but unlike surface streams, the light-limited conditions of the subsurface karst promotes constant heterotrophy leading to carbon turnover. The coupling of the hydrological processes leads to a conceptual model that frames phreatic karst as a biologically active conveyor of sediment carbon that recharges degraded organic carbon back to surface streams. For example, fluvial sediment is estimated to lose 30% of its organic carbon by mass during a one year temporary residence within the phreatic karst. It is recommended that scientists consider karst pathways when attempting to estimate organic matter stocks and carbon transformation in fluvial networks. (C) 2017 Elsevier B.V. All rights reserved.

Our intent was to determine the effectiveness of the 308 rim excimer laser for the treatment of scalp psoriasis through a non‐blinded, randomized, controlled study. Institutional approval for this study was achieved. Twenty consecutive volunteers with stable large plaques of scalp psoriasis were enrolled. Mineral oil was applied before each treatment. A modified psoriasis area severity index (PASI) score was determined before each treatment. Excimer laser generated 308‐rim (Photomedex, San Diego, CA, Model #AL 7000) UV‐13 radiation was administered evenly to each large plaque of scalp psoriasis twice weekly for up to 30 treatments. Untreated areas of adjacent scalp psoriasis served as controls. Each plaque received a set dose of radiation based on a predetermined minimal erythema dose. The dose of radiation was increased incrementally at each visit, as tolerated. There was a clear improvement as assessed by the mean PASI scores for treated vs. untreated plaques of scalp psoriasis. Adverse effects were minimal. The 308 nm excimer laser is a safe, novel and effective method of treating scalp psoriasis.

BACKGROUND:Lichen planus is a difficult-to-treat chronic inflammatory disorder that affects mucous membranes, causing inanition, halitosis, and dyspareunia. OBJECTIVE:To evaluate the novel use of low-dose 308-nm excimer laser radiation for the treatment of symptomatic oral lichen planus (OLP). DESIGN:A single-center, before-after trial. SETTING:Academic clinical research center. PATIENTS:Nine patients with symptomatic, biopsy-proven OLP, unresponsive to conventional therapies, were recruited from the dermatology clinics of the Massachusetts General Hospital in Boston. Eight participants completed the entire study, and 1, despite early improvement, did not complete the study because of hospitalization for an unrelated reason. Intervention With a narrow, fiberoptic handpiece to target precisely only diseased sites, 308-nm excimer laser radiation was delivered at an initial dose of 100 mJ/cm(2) once a week. MAIN OUTCOME MEASURE:A visual analog scale was used to grade subjective disease severity. Clinical improvement was graded in quartiles as follows: poor (<25%), fair (25%-50%), good (51%-75%), and excellent (>75%). Follow-up visits occurred for up to 18 months. A paired t test was performed to evaluate efficacy of treatment. RESULTS:Treatments were painless and well tolerated. Five patients demonstrated overall excellent clinical and subjective improvement after 7 treatments. Two participants with nonerosive OLP were deemed fair responders. The only poor responder in the study also had chronic active hepatitis C infection. Overall improvement was statistically significant (P<.05), and for the responders, remission times ranged from 2 to 17 months. Conclusion Low-dose treatment with the excimer 308-nm laser can be very effective in treating symptomatic and especially erosive OLP, an otherwise notoriously difficult-to-control disease.

Background and Objective Vitiligo is commonly treated with PUVA, and more recently, narrow-band UVB (NBUVB) phototherapy. Given the proximity of the wavelengths of NBUVB (311 nm) and the excimer laser (308 nm), we undertook a clinical trial to test the efficacy of this device.Methods Twice-weekly 308-nm UV-B radiation was given to selected vitiligo lesions for a maximum of 60 treatments. These lesions had been unsuccessfully treated previously with at least one other method of treatment. Initial doses were 100 mJ/cm(2) with increments of 10-25%. Improvement was assessed on a visual scale via serial photographs.Results Subjects tolerated the treatment well. Improvement varied with body site. After 60 treatments, lesions on the hands and feet showed grade 2 improvement in 2/10 subjects and grade 1 in 8/10. For the axillae, there was grade 4 improvement in 1/3 subjects and grade 2 improvement in 2/3 by treatment 60. The face demonstrated the most rapid repigmentation with grade 4 repigmentation seen in 3/5 subjects by 40 treatments and grade 3 in 2/5 by 30 treatments. There were no adverse effects.Conclusions The user-friendly 308-nm excimer laser allows targeted treatments of localized vitiligo.

OBJECTIVE:To determine the response of stubborn psoriatic plaques to the 308-nm excimer laser.DESIGN:Controlled study with a before-after design.SETTING:A university-based clinical research center.PATIENTS:Adult subjects with recalcitrant plaque psoriasis that have not responded to other therapies for at least 2 months.INTERVENTIONS:Selected psoriatic plaques were treated with the 308-nm excimer laser. One lesion was left as a control. Each plaque was treated 2 times a week, with an initial dose based solely on the induration component of the modified Psoriasis Area and Severity Index score for that lesion. Subsequent treatments were twice a week with dosage increments up to 50%, based on the change in induration. Four final consolidation doses were given once the induration score was reduced to zero.RESULTS:Eighteen subjects were treated. There were 4 dropouts because of various scheduling problems. In the remaining 14 subjects, 44 plaques received a mean of 10 treatments (range, 4-14). Treatments were quick and well tolerated. The mean cumulative dose was 8.8 J/cm2 (range, 2.2-22.8 J/cm2). Compared with controls, treated plaques showed significant improvement (P<.001). The only adverse event was a mild sunburn-like reaction in 2 subjects after 1 treatment.CONCLUSIONS:Selective targeting of laser-generated 308-nm excimer radiation with this convenient subblistering dosage schedule based on induration allows for individualized treatment plans for each plaque. Clearing of stubborn psoriatic lesions occurs rapidly and safely.

International Journal of DermatologyVolume 41, Issue 5 p. 282-283 Narrow-band UVB for lichen planus treatment Atul Taneja MD, Corresponding Author Atul Taneja MD Department of Dermatology, Gange Photomedicine Research Center, Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Atul Taneja, MD, Bar 413, 32 Fruit Street (MGH), Boston, MA 02114, USA. E-mail: [email protected]Search for more papers by this authorCharles R. Taylor MD, Charles R. Taylor MD Department of Dermatology, Gange Photomedicine Research Center, Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USASearch for more papers by this author Atul Taneja MD, Corresponding Author Atul Taneja MD Department of Dermatology, Gange Photomedicine Research Center, Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Atul Taneja, MD, Bar 413, 32 Fruit Street (MGH), Boston, MA 02114, USA. E-mail: [email protected]Search for more papers by this authorCharles R. Taylor MD, Charles R. Taylor MD Department of Dermatology, Gange Photomedicine Research Center, Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USASearch for more papers by this author First published: 27 June 2002 https://doi.org/10.1046/j.1365-4362.2002.01499.xCitations: 36Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume41, Issue5May 2002Pages 282-283 RelatedInformation

This work‐in‐progress evaluates the efficacy of a unique UVB fiber optic comb device for treating scalp psoriasis. Informed consent was obtained on 11 enrolled patients. One scalp psoriasis plaque was left as a control, while another was selected for treatment. An MED was performed on the lower back or gluteal skin to determine the subject's baseline sensitivity to the comb device. On the selected sit, mineral oil was first applied with a soaked gauze to enhance UV delivery and the first treatment was at 1 MED. Subsequent treatments were thrice weekly at 72 h intervals with maximum increments of 20% per treatment. Treatments ended after 12 weeks or when clearing occurred, whichever came first. Clinical evaluation and standardized photographs were taken at baseline and every 2 weeks thereafter.Results On average, patients have received 24 treatments (range: 2–36). At baseline, PASI scores for the treated and control sides did not differ significantly (mean difference: 0.4, P= 0.1106). Improvement scores, calculated by subtracting the most recent PASI score from the baseline value, were higher for the treated sides (3.9 vs. 0.3, P = 0.0002).Three patients showed worsening in the control area. Ten of the 11 patients showed improvement in the treated area; none experienced worsening of symptoms.Conclusions The fiber optic brush offers an exciting potential for treating scalp psoriasis.

BACKGROUND:The excimer laser delivers targeted ultraviolet B 308-nm radiation. OBJECTIVE:This investigation evaluated the efficacy of multiple, medium-dose excimer 308-nm laser treatments for psoriasis. METHODS:Twenty volunteers with plaque psoriasis were enrolled. Six plaques received treatment 3 times per week for up to 8 weeks; another plaque served as a control. As in standard phototherapy, a flexible dose escalation scheme was implemented during the course of treatment. Modified Psoriasis Area and Severity Index scores were rendered throughout the study with follow-ups at 1, 2, 4, and 6 months. RESULTS:Fifteen subjects completed the study without complications. The mean number of treatments to achieve >95% clearance was 10.6. The mean cumulative UV radiation dose was 6.1 J/cm(2), and the mean remission time was 3.5 months. CONCLUSION:A thrice-weekly, medium-dose irradiation schedule with the 308-nm laser can effectively clear localized plaque-type psoriasis in fewer treatments with an overall lower cumulative dose, compared with standard phototherapy. This innovative UV device allows specific targeting of affected sites without needless exposure of unaffected skin.

The excimer 308 nm laser has recently been FDA‐approved in the United States for the treatment of psoriasis. Our center was the first to study this device systematically for this indication. Investigations to date have included an initial dose‐response study, a high‐dose as well as a medium‐dose one. Collectively, these results were analyzed and remission periods were reviewed. The rapidity of clearing as well as the severity of side‐effects showed a clear dose‐response relationship. Even thick plaques responded. The treatment process itself is quick and painless, allowing the operator to cover a palm‐sized area in just a minute. The laser is easy to use and there are no disfiguring purpura. By selectively focusing on lesional skin, overall cutaneous ultraviolet burden is minimized. Localized tanning is another side‐effect to be anticipated. Obviously, blistering doses show limited applicability as the sole treatment for extensive disease. Moreover, the long‐term risks associated with blistering directly on plaques of psoriasis themselves, while not clearly established, seem unlikely to be favorable. On the other hand, sub‐blistering doses appear to be extremely well‐tolerated. Wound care, except in the cases of blistering doses, is minimal. In short, the 308 nm excimer laser offers a novel targeted treatment modality for localized psoriasis, even when the plaques are quite thick.

GroundwaterVolume 39, Issue 6 p. 801-801 Free Access The Value of Long-Term Ground Water Level Monitoring William M. Alley, William M. Alley Chief, Office of Ground Water, U.S. Geological Survey, Reston, Virginia.Search for more papers by this authorCharles J. Taylor, Charles J. Taylor Hydrologist, U.S. Geological Survey, Louisville, Kentucky.Search for more papers by this author William M. Alley, William M. Alley Chief, Office of Ground Water, U.S. Geological Survey, Reston, Virginia.Search for more papers by this authorCharles J. Taylor, Charles J. Taylor Hydrologist, U.S. Geological Survey, Louisville, Kentucky.Search for more papers by this author First published: 13 December 2005 https://doi.org/10.1111/j.1745-6584.2001.tb02466.xCitations: 11AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References Taylor, C.J., and W.M Alley. 2001. Ground-water-level monitoring and the importance of long-term water-level data. U.S. Geological Survey Circular 1217. Citing Literature Volume39, Issue6November 2001Pages 801-801 ReferencesRelatedInformation

This report describes the results of a sampling event conducted at the Distler Brickyard Superfund Site, Hardin County, Kentucky, October 1999. The purpose of the sampling event was to evaluate the extent of natural biodegradation of chlorinated aliphatic hydrocarbons (CAH) occurring at the Site. Sampling locations were selected to evaluate three areas of the suspected CAH plume: the source area, an axial cross-section, and a downgradient transect. Due to inadequate recharge to and the poor physical condition of some monitoring wells at the Site, the sampling approach was modified to reflect wells that could be sampled. Results indicate that natural anaerobic degradation of chlorinated aliphatic hydrocarbons is occurring in the presumed source area around monitoring well GW-11. The primary contaminant of concern, trichloroethene, migrates downgradient from the source area into the Coarse Grained Alluvium Aquifer at concentrations slightly greater than the Maximum Contaminant Level (MCL). Based on the available, the following hypothesis is proposed: the source area has been remediated through soil removal activities and subsequent anaerobic reductive dechlorination. If this is the case, this Site may be a good candidate for implementation of a monitored natural attenuation remedy. However, more data are necessary before this hypothesis can be confirmed.

This report describes the results of groundwater and soil gas sampling conducted at the Distler Brickyard Site, Hardin County, Kentucky, June-August, 2000. The purpose of the sampling activities was to address remaining data gaps regarding the feasibility of monitored natural attenuation (MNA) for remediation of chloroethene/ane contamination. Specifically, data gaps fall into four categories: 1) effect of seasonal recharge on contaminant concentrations, 2) geochemical conditions in the Fine Grained Alluvium (FGA), 3) conditions along the flowpath between Wells GW-11 and MW-3, and 4) the extent of aerobic degradation in the Coarse Grained Alluvium (CGA). A data collection strategy composed of both groundwater sampling and passive soil vapor sampling devices (Gore-Sorbers?) was used. The Gore-Sorber? technology was used to collect data from the FGA, which because of its low hydraulic conductivity and variable saturation makes collection of groundwater samples problematic. Gore-Sorbers were deployed in 15 wells, most of them being in the FGA, and groundwater samples were collected in 17 wells, which were mostly in the CGA. Both sampling methods were utilized in a subset of wells (7) in order to determine the general comparability of results obtained from each method. Results indicate that water levels in both the FGA and CGA were higher in June-August 2000 than in October 1999, likely due to increased infiltration of precipitation through the FGA during the wetter months. Redox conditions in the FGA and downgradient CGA were iron-reducing, less reducing than in October-1999. In general, concentrations of chloroethenes/anes were higher in June-August 2000 than October 1999. Trichloroethene (TCE) was present at concentrations as high as 65 µg/L in the FGA and 19 µg/L in the CGA. This is substantially higher than the maximum concentration in October 1999 of 11 µg/L. The following conclusions were drawn from these data collection activities: 1) two potential contaminant source areas remain at the site, 2) redox conditions are less reducing than October 1999, 3) anaerobic reductive dechlorination (ARD) continues to take place in the FGA, and 4) seasonal fluctuations in recharge affect water levels, redox conditions, contaminant concentrations, and ARD reactions. Possible final remedial response actions include 1) monitored natural attenuation, 2) monitored natural attenuation with physical source removal, or 3) monitored natural attenuation with source removal via enhanced ARD. All of these remedies will require the collection of additional data in three areas: 1) the nature and extent of the GW-3/UDBW-11 source area and the flux rate and fate of contaminants from it, 2) the magnitude and timing of recharge fluctuations, and 3) the local hydraulic gradient and groundwater flow directions. Each remedy may also have specific additional data collection requirements. This document will serve as the basis for the selection of the appropriate remedy by the state and federal regulators.

OBJECTIVE:To determine the dose-response relationship of excimer laser-generated 308-nm UV-B radiation for treating psoriasis.DESIGN:Pilot study with a before-after design.SETTING:A university dermatology service.PATIENTS:Thirteen consecutive patients with at least 4 large, stable psoriasis plaques.INTERVENTIONS:Excimer laser-generated 308-nm UV-B radiation was given to each of 4 plaques, which received 1, 2, 4, and 20 treatments, respectively. Untreated areas within each plaque served as controls. Within each plaque, 8 doses based on multiples of a predetermined minimal erythema dose (MED) were tested in distinct sites. The multiples were 0.5 and 1 (low dose); 2, 3, 4, and 6 (medium dose); and 8 and 16 (high dose). At every treatment, the dose for each site remained fixed at the same MED multiple. A psoriasis severity index score was determined for each area before, every 2 weeks during, and 2 and 4 months after treatment.RESULTS:The mean+/-SD MED was 203.03+/-57.84 mJ/ cm2. Treatment with high fluences produced significantly better results than that with medium and low fluences at weeks 4, 6, 8, and 10 (P<.05). At 4 months' follow-up, all sites that received low or medium fluences had recurrences, whereas those that underwent a single treatment at 8 and 16 MED multiples remained in remission.CONCLUSIONS:With 308-nm UV-B radiation generated by an excimer laser, it is possible to clear psoriasis with as little as 1 treatment with moderately long remission. In contrast to traditional phototherapy techniques, this handheld excimer laser UV-B therapy is selectively directed toward lesional skin, thus sparing the surrounding normal skin from unnecessary radiation exposure. Treatment of other inflammatory diseases and limited psoriasis seems reasonable to pursue with this modality.

Background: Treatment of recalcitrant psoriatic plaques located on certain areas of the body remains problematic despite the many therapeutic options available. Objective: This study was conducted to determine the efficacy of Pendulaser carbon dioxide (CO2) resurfacing laser to that of electrodesiccation with curettage in the treatment of recalcitrant psoriatic plaques. Methods: A single psoriatic plaque was divided into thirds, one part treated with CO2 resurfacing laser, another with electrodesiccation and curettage, and the third left untreated. The psoriatic epidermis and papillary dermis were removed by the two treatment modalities. Results: CO2 resurfacing laser and electrodesiccation with curettage produced similar therapeutic effects in terms of improvement of psoriasis and were significantly better than the control 4 months later, but not at 6 months. Conclusion: For limited recalcitrant psoriatic plaques, CO2 resurfacing laser and electrodesiccation with curettage may provide an alternative short-term treatment; however, caution must be exercised and the moderately high risk of scarring carefully weighed against the potential benefits. (J Am Acad Dermatol 2000;42:660-6.)

We describe a man with Kimura's disease whose presentation included lymphadenopathy and cutaneous nodules, but was most distinctive for painful oral ulcerations. His lesions showed an initially moderate, but ultimately minimal response to monthly triamcinolone injections. With oral pentoxyifylline, he showed resolution of all of his lesions for 14 months. On cessation of his treatment, his disease flared for 3 months. When pentoxyifylline was restarted, his lesions regressed again within 4 weeks. We review the literature on Kimura's disease.

Topical aminolevulinic acid is converted into a potent photosensitizer, protoporphyrin, in human hair follicles and sebaceous glands. Photodynamic therapy with topical aminolevulinic acid was tested for the treatment of acne vulgaris, in an open-label prospective human study. Each of 22 subjects with acne on the back was treated in four sites with aminolevulinic acid plus red light, aminolevulinic acid alone, light alone, and untreated control. Half of the subjects were treated once; half were treated four times. Twenty percent topical aminolevulinic acid was applied with 3 h occlusion, and 150 J per cm2 broad-band light (550-700 nm) was given. Sebum excretion rate and auto-fluorescence from follicular bacteria were measured before, and 2, 3, 10, and 20 wk after, treatment. Histologic changes and protoporphyrin synthesis in pilosebaceous units were observed from skin biopsies. Aminolevulinic acid plus red light caused a transient acne-like folliculitis. Sebum excretion was eliminated for several weeks, and decreased for 20 wk after photodynamic therapy; multiple treatments caused greater suppression of sebum. Bacterial porphyrin fluorescence was also suppressed by photodynamic therapy. On histology, sebaceous glands showed acute damage and were smaller 20 wk after photodynamic therapy. There was clinical and statistically significant clearance of inflammatory acne by aminolevulinic acid plus red light, for at least 20 wk after multiple treatments and 10 wk after a single treatment. Transient hyperpigmentation, superficial exfoliation, and crusting were observed, which cleared without scarring. Topical aminolevulinic acid plus red light is an effective treatment of acne vulgaris, associated with significant side-effects. Aminolevulinic acid plus red light causes phototoxicity to sebaceous follicles, prolonged suppression of sebaceous gland function, and apparent decrease in follicular bacteria after photodynamic therapy. Potentially, aminolevulinic acid plus red light may be useful for some patients with acne.

Dr Lawrence Khoo and Dr Charles Taylor have reviewed the literature concerning ultraviolet light therapy for atopic dermatitis including conventional broad-band UVB, UVA, UVA-1 and narrow-band UVB. They have also examined the evidence for treatment of eczema with PUVA and ambient sunlight. This detailed review serves to bring residents and trainees up-to-date with the various phototherapies used to treat atopic eczema and in particular places narrow-band UVB firmly within this repertoire of therapies. Narrow-band UVB phototherapy has moved from being a research based phototherapy offered in a small number of specialized photodermatology units in Europe to being widely available in phototherapy units throughout the world. This rapid development is a reflection of the obvious efficacy of narrow-band UVB in the treatment of psoriasis and has close parallels with the development of PUVA. As with PUVA there is now accumulating evidence that narrow-band UVB phototherapy has a role in the treatment of recalcitrant cases of atopic dermatitis.