NOVEL FIBER OPTIC TIP DESIGNS AND DEVICES FOR LASER SURGERY

Fiber optic delivery of laser energy has been used for years in various types of surgical procedures in the human body. Optical energy provides several benefits over electrical or mechanical surgery, including the ability to selectively target specific tissue types while preserving others. Specialty fiber optic tips have also been introduced to further customize delivery of laser energy to the tissue. Recent evolution in lasers and miniaturization has opened up opportunities for many novel surgical techniques. Currently, ophthalmic surgeons use relatively invasive mechanical tools to dissect retinal deposits which occur in proliferative diabetic retinopathy. By using the tight focusing properties of microspheres combined with the short optical penetration depth of the Erbium:YAG laser and mid-IR fiber delivery, a precise laser scalpel can be constructed as an alternative, less invasive and more precise approach to this surgery. Chains of microspheres may allow for a self limiting ablation depth of approximately 10 µm based on the defocusing of paraxial rays. The microsphere laser scalpel may also be integrated with other surgical instruments to reduce the total number of handpieces for the surgeon. In current clinical laser lithotripsy procedures, poor input coupling of the Holmium:YAG laser energy frequently damages and requires discarding of the optical fiber. However, recent stone ablation studies with the Thulium fiber laser have provided comparable results to the Ho:YAG laser. The improved spatial beam profile of the Thulium fiber laser can also be efficiently coupled into a fiber approximately one third the diameter and reduces the risk of damaging the fiber input. For this reason, the trunk optical fiber minus the distal fiber tip can be preserved between procedures. The distal fiber tip, which degrades during stone ablation, could be made detachable and disposable. A novel, low-profile, twist-locking, detachable distal fiber tip interface was designed, assembled, and tested for use in Thulium fiber laser lithotripsy. A 1.00-mm-outer- diameter detachable fiber tip interface was designed, constructed, and tested ex vivo on urinary stones in the laboratory. Similar stone ablation rates between the previously studied tapered distal fiber tip and the detachable fiber tip were measured. For urologists desiring faster TFL lithotripsy procedures, the incorporation of detachable distal fiber tips allows for rapid replacement of damaged fiber tips without concern about the laser to trunk fiber connection. This method for preserving the trunk fiber could be a motivation for integrating a dedicated laser fiber into the ureteroscope, with detachable distal tips, thus freeing the working channel for the use of other surgical instruments. During laser lithotripsy, distal fiber tip degradation increases as the fiber core diameter decreases. However, smaller fiber diameters ( = 200 µm ) are more desirable because of increased saline irrigation rates in the single working channel of the ureteroscope and less impact on ureteroscope deflection. A hollow fiber cap is proposed to reduced fiber tip degradation in small diameter fibers, without compromising stone ablation rates. The disadvantage of the hollow fiber tip observed in the study is the increase in stone retropulsion. However, integrating the hollow fiber tip with a clinically used stone basket may allow for a robust stone ablation instrument that also minimizes retropulsion. These surgical approaches involving novel specialty fiber optic tip designs are discussed in this thesis

Predicting positive career planning attitudes among division I college student-athletes

This study examined the extent that athletic identity, race, gender, sport and expectation to play professionally predict Career Planning Attitudes (Career Optimism, Career Adaptability and Career Knowledge) among Division I college student-athletes. Participants of this study consisted of 538 Division I student-athletes from four Bowl Championship Series institutions, and these student-athletes were given a demographic questionnaire, Athletic Identity Measurement Scale and Career Futures Inventory. Results of this study found that male Division I student-athletes believed they had a better understanding of the job market and employment trends than their female counterparts. Division I student-athletes with higher athletic identities had lower levels of career optimism. Male Division I student-athletes had more career optimism than female Division I student-athletes. Division I student-athletes who participated in revenue- producing sports had lower levels of career optimism. Student-athletes with a higher expectation to play professional sports were more likely to be optimistic regarding their future career. Female Division I student-athletes had higher levels of athletic identity than their male counterparts. Student-athletes with a higher expectation to play professionally displayed higher athletic identities

Changing trends in pseudoretinoblastoma diagnoses: A 10 year review from the United Kingdom

AIM:To study the different types and frequency of pseudoretinoblastoma (pseudoRB) lesions who present to a retinoblastoma centre due to concern that the condition may be retinoblastoma. METHODS: A retrospective chart review of 341 patients presenting sporadically to the Royal London Hospital from January 2009 to December 2018. RESULTS: 220 patients (65%) were confirmed to have retinoblastoma, while 121 (35%) had pseudoRB. There were 23 differential diagnoses in total. The top 3 differential diagnoses were Coats’ disease (34%), Persistent Foetal Vasculature (PFV) (17%) and Combined Hamartoma of Retina and Retinal Pigment Epithelium (CHR-RPE) (13%). PseudoRBs differed with age at presentation. Under the age of 1 (n = 42), the most likely pseudoRB conditions were PFV (36%), Coats’ disease (17%) and CHR-RPE (12%). These conditions were also the most common simulating conditions between the ages of 1 and 2 (n = 21), but Coats’ disease was the most common in this age group (52%), followed by CHR-RPE (19%) and PFV (14%). Between the ages of 2 and 5 (n = 32), Coats’ disease remained the most common (44%) pseudoRB lesion followed by CHR-RPE (13%), or PFV, Retinal Astrocytic Hamartoma (RAH), familial exudative vitreoretinopathy (FEVR) (all 6.3%). Over the age of 5 (n = 26), pseudoRBs were most likely to be Coats’ disease (35%), RAH (12%), Uveitis, CHR-RPE, FEVR (all 7.7%). CONCLUSION: 35% of suspected retinoblastoma cases are pseudoRB conditions. Overall, Coats’ disease is the most common pseudoRB condition, followed by PFV. Hamartomas (CHR-RPE & RAH) are more prevalent in this cohort, reflecting improvements in diagnostic accuracy from referring ophthalmologists

Seasonal Carbohydrate Dynamics and Climatic Regulation of Senescence in the Perennial Grass, Miscanthus

Miscanthus is a perennial energy grass predominantly used for combustion but there is increasing interest in fermenting the cell-wall carbohydrates or green-cutting for soluble sugars to produce bioethanol. Our aims were to: (1) quantify non-structural carbohydrates (NSC), (2) observe the timing of seasonal shifts in the stems and rhizome, and (3) identify developmental and/or climatic conditions that promoted carbohydrate remobilization from the stems to the rhizome during senescence. Two genotypes of Miscanthus sinensis, a Miscanthus sacchariflorus and a Miscanthus × giganteus were grown at replicated field sites in Aberystwyth, West Wales and Harpenden, South East England. NSC were quantified from the rhizome and aboveground organs and then correlated with climatic data collected from on-site weather stations. PAR and maximum daily temperatures were higher at Harpenden throughout the year, but daily minimum temperatures were lower. Senescence was accelerated at Harpenden. Carbohydrates were retained within the stems of non-flowering genotypes, at both sites, in winter and were still present after a frost event to −2 °C. Rhizome starch concentrations were at least equal to the previous winter’s levels (February 2011) by September. Lower daily minimum temperatures accelerate the rate of senescence and warmer daily maximum temperatures cannot counteract this effect. At current yields, M. × giganteus, could produce 0.7 t ha−1 of NSC in addition to ligno-cellulosic biomass in November but with concerted breeding efforts this could be targeted for improvement as has been achieved in other crops. Shifting harvests forward to November would not leave the rhizome depleted of carbohydrates

Collecting wild Miscanthus germplasm in Asia for crop improvement and conservation in Europe whilst adhering to the guidelines of the United Nations’ Convention on Biological Diversity

We would like to thank Dr Helen Ougham and Professor Howard Thomas for their valuable comments on this manuscript; Sarah Hawkins at IBERS for the leading of harvesting and phenotyping works; and Paul Barber at Plant Health and Seeds Inspectorate, Wales & West Midlands, Animal and Plant Health Agency (APHA) for advice on germplasm collection practice and quarantine management. This research was supported by the UK’s Department for Environment, Food and Rural Affairs (Defra) under a project entitled ‘Accession of CBD compliant Miscanthus and Triarrhena germplasm from China, Japan and Taiwan for incorporation in the UK Miscanthus breeding programme’ [grant no. NF0436]. The breeding and evaluation were conducted under ‘Genetic improvement of Miscanthus as a sustainable feedstock for bioenergy in the UK (GIANT)’ [supported by Defra and the Biotechnology and Biological Sciences Research Council (BBSRC http://dx.doi.org/10.13039/501100000690, ‘Research Councils UK’), UK, grant no. LK0863]. LH, ID and JCB were supported by BBSRC grant nos BBS/E/G/00003134 and BBS/E/W/0012843A.Peer reviewedPublisher PD

Progress in upscaling Miscanthus biomass production for the European bio-economy with seed-based hybrids

Funded by UK's Biotechnology and Biological Sciences Research Council (BBSRC) Department for Environment, Food and Rural Affairs (DEFRA). Grant Number: LK0863 BBSRC strategic programme Grant on Energy Grasses & Bio-refining. Grant Number: BBS/E/W/10963A01 OPTIMISC. Grant Number: FP7-289159 WATBIO. Grant Number: FP7-311929 Innovate UK/BBSRC ‘MUST’. Grant Number: BB/N016149/1Peer reviewedPublisher PD

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead