Analogy Powered by Prediction and Structural Invariants: Computationally Led Discovery of a Mesoporous Hydrogen-Bonded Organic Cage Crystal.

Mesoporous molecular crystals have potential applications in separation and catalysis, but they are rare and hard to design because many weak interactions compete during crystallization, and most molecules have an energetic preference for close packing. Here, we combine crystal structure prediction (CSP) with structural invariants to continuously qualify the similarity between predicted crystal structures for related molecules. This allows isomorphous substitution strategies, which can be unreliable for molecular crystals, to be augmented by a priori prediction, thus leveraging the power of both approaches. We used this combined approach to discover a rare example of a low-density (0.54 g cm-3) mesoporous hydrogen-bonded framework (HOF), 3D-CageHOF-1. This structure comprises an organic cage (Cage-3-NH2) that was predicted to form kinetically trapped, low-density polymorphs via CSP. Pointwise distance distribution structural invariants revealed five predicted forms of Cage-3-NH2 that are analogous to experimentally realized porous crystals of a chemically different but geometrically similar molecule, T2. More broadly, this approach overcomes the difficulties in comparing predicted molecular crystals with varying lattice parameters, thus allowing for the systematic comparison of energy-structure landscapes for chemically dissimilar molecules.

Bromelain-based enzymatic debridement of e-cigarette burns: a single unit experience.

OBJECTIVE: It is widely accepted that the early debridement of burns improves outcome. There is increasing evidence that enzymatic debridement is an effective technique for removal of full-thickness and deep-dermal burns, reducing blood loss and often the need for autologous skin grafting by avoiding over excision of the burn. We aim to highlight the potential use of this form of debridement as an alternative to surgical management in patients with electronic cigarette (e-cigarette)-associated flame burn injuries. METHODS: This case series presents the use of Nexobrid (MediWound Ltd, Israel), a non-surgical, bromelain-based enzymatic debridement technique, in patients with deep partial-thickness burns (range: 1-3% total body surface area), avoiding the need for autologous skin grafting. RESULTS: Burn wounds in two patients healed within 14 days without complications or the need for further surgical intervention. Another patient required further dressings after discharge but failed to attend follow-up appointments. These results are comparable with those reported by others using conservative management of e-cigarette burns. CONCLUSION: The authors wish to raise awareness of the potential for a combination of thermal and chemical burns related to e-cigarette explosions. Chemical burns should be excluded by pH testing of the burn wound. From our experience, small e-cigarette-associated flame burns can be considered for management with enzymatic debridement.

E-cigarette burn injuries: Comprehensive review and management guidelines proposal.

INTRODUCTION: Electronic cigarettes (EC) have been reported to be associated with burns secondary to explosions of the device or battery, or contact from overheating, resulting in flame, contact or chemical burns. In addition to this, there have also been reported cases of soft tissue and bony trauma with or without associated burns. Using collective evidence, this review aims to summarise all reported burns associated with ECs, and its implications on immediate management with a particular focus on surgical treatment. METHODS: A search was conducted on PubMed, EMBASE and Medline for all case reports, case series and letters to editors published since 2014, using terms "electronic cigarette", "e-cigarette", "vaping" and "burn". The search was repeated by the co-author to avoid bias and a review of the bibliographies of each paper was conducted to ensure all relevant cases were included. The mechanisms, type and severity of burn injury, and management and treatment outcomes of the patients were recorded. Exclusion criteria included non-English articles, explosions with no associated burn and publications with insufficient information. RESULTS: 90 patients from 19 case series or case reports were included. With the exception of one study, gender was recorded with a male predominance (95.6%). Mean age is 30.1years (range 18-59). The most common type of burn was flame. However, there were reports of chemical burns associated with ECs. The mean total body surface area (TBSA) affected was 4.9% (range 1-27.25%) with the majority of burns being mixed partial and full thickness. 22 patients underwent excision and autologous skin grafting within range of three to 21days. One patient had a full thickness contact burn excised and closed, one patient received a xenograft following debridement and one had biosynthetic skin dressing. 42 patients were managed conservatively with dressings or ointments. DISCUSSION: In this review over a three-year period (2015-2017), 90 cases of EC related burn injuries were reported, however, this is likely an underestimation of the problem. The suggested mechanism for EC related injuries is battery malfunction. ECs are powered by Lithium ion batteries which are susceptible to "thermal runaway" reactions, which result in device overheating with potential for subsequent explosion. We explain hypothesized triggers for these reactions and mechanisms of other injuries associated with ECs such as chemical burns and blast injury. CONCLUSION: EC-associated burn injury results in combined thermal and chemical burns, which should be managed in tandem. Explosion injuries sustained whilst using the device may result in both facial trauma or inhalation injury and therefore should be reviewed with a high index of clinical suspicion. It is noted that there is no agreed standard for management for such burns by specialist bodies in the UK. We suggested a treatment algorithm to provide guidance for the burn injuries associated with ECs.

Adverse effects reported in epilatory ruby laser treatment.

A retrospective study was conducted to investigate the incidence of reported adverse responses after epilatory laser treatment to control the growth of facial hair in patients with polycystic ovary syndrome. Forty-eight patients received a median of 6 (range 2-11) treatments with an Aesculap ruby laser during a 704 day monitoring period at Salisbury District Hospital. Nine adverse skin responses such as blistering, scabbing, sustained localised erythematous reactions or hyperpigmentation were reported. The energy output of the laser was also recorded at the start of every clinical session during this period using an external energy meter. The measured energy output of the laser was plotted alongside incidents of adverse responses, although no statistically significant correlation was found. The question of whether or not some adverse effects in ruby laser treatment can be attributed to laser performance remains open.

Monitoring the ups and downs of pulsed dye laser energy output.

The internal energy meter reading of a Chromos pulsed dye laser (PDL) set at 50% of maximum pumping energy was recorded at the start of every clinical session over an 898 day period and compared with the measurement from an Ophir Optronics 'Nova' external energy meter. This quick and inexpensive process improved quality control procedures for the use of the PDL and enabled the performance of laser components such as the dye, pumping mechanism and optics to be monitored. The stability of the laser output energy was also monitored during three simulated clinics on days 665, 870 and 898. External energy meter readings were recorded every 100 pulses during each simulated clinic comprising six series of 500 pulses. As the energy output was shown to be stable during each clinic (SD<4.7%) recalibration during treatments of up to 500 pulses with this laser was deemed to be unnecessary. However, it was noted that this output energy stability was maintained by varying the pumping energy from 42 to 88% of maximum. Subsequent measurements of pulse width conducted with an ET-2000 Silicon Photodetector demonstrated that although the nominal pulse width was 450 mus, this varied from 240 to 390 mus as the pumping energy increased from 20 to 50%.

How well does your ruby laser work?

The safe and effective use of cutaneous lasers is dependent upon the selection of a clinically appropriate laser energy level. Therefore, the accuracy of the stated laser output is critical. The energy output of an Aesculap ruby laser was recorded at the start of every clinical session over a 704-day period using an external energy meter. Regular review of these records enabled trends of energy output to be recognised and appropriate action to be taken prior to adverse clinical sequelae. This monitoring procedure is a quick and inexpensive method of improving quality control in the use of medical lasers.