Tracking Defects and Microstructural Heterogeneities in Meso-Scale Tensile Specimens Excised from Additively Manufactured Parts.

The commercialization of additive manufacturing (AM) is underway in the aerospace and biomedical device industries [1, 2]. However, most metal parts produced by AM are limited to non-critical applications, since the various processes produce internal porosity, anisotropy, and microstructural heterogeneities [1, 3]. It has been implied that small-scale mechanical tests can advance measurement standards for AM applications by probing the effects of defects and heterogeneities on mechanical properties at more appropriate length scales [4, 5]. Traditionally, small-scale techniques have been used to characterize location- and orientation-specific mechanical properties in wrought materials [6-10]. A common method for excising mechanical test specimens from bulk parts with negligible influence on specimen integrity involves electrical discharge machining (EDM) [11]. This work demonstrates that excising meso-scale tensile specimens from additively manufactured parts enables tracking of sub-surface and visible features of interest (porosity and microstructural heterogeneities) throughout the entire gauge section such that the individual contributions to deformation behavior can be assessed.

The impact of coronavirus disease 2019 on suspected head and neck cancer two-week-wait referrals.

BACKGROUND: The impact of coronavirus disease 2019 extends far beyond the immediate burden on healthcare systems caused by hospitalisation of patients with the disease itself. OBJECTIVE: To investigate the impact of the coronavirus disease 2019 pandemic on the referral rate of patients to the suspected head and neck cancer two-week-wait clinic. METHODS: A multicentre retrospective study was performed investigating data collected for all patients attending the suspected head and neck cancer two-week-wait clinic in ENT departments in the West Midlands. RESULTS: A total of 509 fast-track referrals were received from February to April in 2019, compared to 399 referrals in 2020. April 2020 saw a 62.4 per cent reduction in referral rate compared to April 2019. CONCLUSION: The coronavirus disease 2019 pandemic has resulted in changes to health-seeking behaviours, and healthcare provision and delivery. Urgent policy interventions may be required to compensate for the hidden impact that the coronavirus disease 2019 pandemic has had on those with cancer.

Tears evaluation of one sample of keratoconus patients in kuala lumpur.

OBJECTIVE: To evaluate tears of newly diagnosed keratoconus patients attending the Optometry clinic in Malaysia and to compare this with tears of normal myopic subjects. METHODS: The ocular surface of newly diagnosed keratoconus patients were evaluated using tear break up time (TBUT) test, non invasive tear break up time test (NIBUT) and Schirmer test. Twenty keratoconus patients (40 eyes) and 40 normal subjects (80 eyes) participated in this study. RESULTS: Significantly lower TBUT and NIBUT values were found in keratoconus patients than normal control subjects (p<0.05). Mean TBUT and NIBUT for keratoconus patients were 3.99±1.69s and 7.03±3.48s and for normal subjects were 7.24±4.39s and 13.67±10.81s respectively. However, no significant difference was detected in Schirmer test values. Mean values of Schirmer tests I and II for keratoconus patients were 20.52±10.66mm and 10.71±10.43mm and for normals were 23.83±11.34mm and 13.27±8.28mm accordingly. CONCLUSION: It was concluded from this study that keratoconus patients have poor tear stability which need to be considered appropriately during management of the patients.

Overcoming Radioresistance: Small Molecule Radiosensitisers and Hypoxia-activated Prodrugs.

The role of hypoxia in radiation resistance is well established and many approaches to overcome hypoxia in tumours have been explored, with variable success. Two small molecule strategies for targeting hypoxia have dominated preclinical and clinical efforts. One approach has been the use of electron-affinic nitroheterocycles as oxygen-mimetic sensitisers. These agents are best exemplified by the 5-nitroimidazole nimorazole, which has limited use in conjunction with radiotherapy in head and neck squamous cell carcinoma. The second approach seeks to leverage tumour hypoxia as a tumour-specific address for hypoxia-activated prodrugs. These prodrugs are selectively activated by reductases under hypoxia to release cytotoxins, which in some instances may diffuse to kill surrounding oxic tumour tissue. A number of these hypoxia-activated prodrugs have been examined in clinical trial and the merits and shortcomings of recent examples are discussed. There has been an evolution from delivering DNA-interactive cytotoxins to molecularly targeted agents. Efforts to implement these strategies clinically continue today, but success has been elusive. Several issues have been identified that compromised these clinical campaigns. A failure to consider the extravascular transport and the micropharmacokinetic properties of the prodrugs has reduced efficacy. One key element for these 'targeted' approaches is the need to co-develop biomarkers to identify appropriate patients. Hypoxia-activated prodrugs require biomarkers for hypoxia, but also for appropriate activating reductases in tumours, as well as markers of intrinsic sensitivity to the released drug. The field is still evolving and changes in radiation delivery and the impact of immune-oncology will provide fertile ground for future innovation.

A meta-analysis of local anesthesia for transrectal ultrasound-guided biopsy of the prostate.

This meta-analysis evaluated the efficacy and safety of periprostatic nerve block (PPNB) and intrarectal local anesthestic (IRLA) gel in alleviating pain during prostate biopsy. Electronic databases MEDLINE, Cochrane Central Register of Controlled Trials and EMBASE were searched to identify all randomized controlled trials comparing PPNB with periprostatic placebo injection, no injection or with IRLA. Studies for inclusion were identified and extracted by two authors independently. The main outcome measure was patients' assessment of mean pain scores on a 10-point scale at the end of the biopsy procedure. Secondary outcomes were complications and adverse events. Continuous data from the trials were combined by calculating the weighted mean difference (WMD) with its 95% confidence interval. In total, 25 studies met the inclusion criteria. Twenty studies involving 1685 patients compared PPNB with either no anesthesia or with placebo injection controls, showing a significant reduction in pain score in the anesthetic group (WMD -2.09, 95% CI -2.44 to -1.75, P<0.00001). Five studies with 466 patients compared IRLA and control. Although IRLA was associated with pain reduction, the effect size was not statistically significant (WMD -0.22, 95% CI -0.56 to 0.12). Six studies with 872 patients compared PPNB with IRLA, showing a significant pain reduction in the former group (WMD -1.53, 95% CI -2.67 to -0.39, P=0.008). No trials reported an increase in complications in the treatment arms. In conclusion, the evidence from randomized controlled trials shows that local anesthetic given as a PPNB, but not as an intrarectal instillation, is effective and safe in alleviating pain from transrectal ultrasound biopsy of the prostate.

Adult Co-morbidity Evaluation 27 scores of head and neck cancer patients using touch-screen technology: patient satisfaction and clinical verification.

OBJECTIVES: This study aimed to assess head and neck cancer patient satisfaction with the use of a touch-screen computer patient-completed questionnaire for assessing Adult Co-morbidity Evaluation 27 co-morbidity scores prior to treatment, along with its clinical reliability. METHODS: A total of 96 head and neck cancer patients were included in the audit. An accurate Adult Co-morbidity Evaluation 27 co-morbidity score was achieved via patient-completed questionnaire assessment for 97 per cent of participants. RESULTS: In all, 96 per cent of patients found the use of a touch-screen computer acceptable and would be willing to use one again, and 62 per cent would be willing to do so without help. Patients were more likely to be willing to use the computer again without help if they were aged 65 years or younger (χ2 test; p = 0.0054) or had a performance status of 0 or 1 (χ2 test; p = 0.00034). CONCLUSION: Use of a touch-screen computer is an acceptable approach for assessing Adult Co-morbidity Evaluation 27 scores at pre-treatment assessment in a multidisciplinary joint surgical-oncology clinic.

Bilateral hearing loss following electrocution.

Electrocution is a rare cause of sensorineural deafness. We describe and discuss the first reported case in this country of domestic electrocution resulting in a bilateral sensorineural deafness.

A chip-scale atomic clock based on 87Rb with improved frequency stability.

We demonstrate a microfabricated atomic clock physics package based on coherent population trapping (CPT) on the D1 line of 87Rb atoms. The package occupies a volume of 12 mm3 and requires 195 mW of power to operate at an ambient temperature of 200 degrees C. Compared to a previous microfabricated clock exciting the D2 transition in Cs [1], this 87Rb clock shows significantly improved short- and long-term stability. The instability at short times is 4 x?10-11 / tau?/2 and the improvement over the Cs device is due mainly to an increase in resonance amplitude. At longer times (tau?> 50 s), the improvement results from the reduction of a slow drift to ?5 x 10-9 / day. The drift is most likely caused by a chemical reaction of nitrogen and barium inside the cell. When probing the atoms on the D1 line, spin-exchange collisions between Rb atoms and optical pumping appear to have increased importance compared to the D2 line.

Protection of human gastric mucosa against aspirin-enteric coating or dose reduction?

BACKGROUND: Aspirin is widely used for cardiovascular prophylaxis. AIM: To compare the effectiveness of two widely-used strategies-dose reduction and enteric coating-for the minimization of gastric mucosal injury or toxicity. METHODS: Twelve healthy volunteers were studied. On four separate occasions each received, under blinded conditions, five daily doses of plain aspirin 300 mg, plain aspirin 75 mg, enteric-coated aspirin 300 mg or placebo. Ex vivo prostaglandin E2 synthesis was stimulated by the vortex mixing of gastric mucosal biopsies in Tris saline and measured by radioimmunoassay. Mucosal injury was quantified both by counting erosions and with a visual analogue scale. RESULTS: All three preparations reduced prostaglandin E2 synthesis by day five, by (median) 84% for plain aspirin 300 mg, by 80% for enteric coated aspirin 300 mg and by 63% for plain aspirin 75 mg. There was little mucosal injury prior to the start of each dose and period and no significant change with placebo. Plain aspirin caused a dose-dependent mucosal injury, with two (median, IQR 0-7) gastric erosions after five days of plain aspirin 75 mg, and 18 (2-26) after five days of plain aspirin 300 mg. With enteric-coated aspirin 300 mg there were 0 (0-1) gastric erosions (P = 0.003 compared to plain aspirin 300 mg P = 0.11, compared to plain aspirin 75 mg). CONCLUSION: Enteric coated aspirin reduces acute gastric mucosal injury to placebo levels, despite its inhibition of prostaglandin synthesis. Enteric coating is an appropriate strategy for the prevention of gastric mucosal damage induced by low-dose aspirin, which warrants systematic clinical evaluation.

Effects of aminoacids on the autooxidation of 3,5-di-tert-butylcatechol in the presence of surface-active copper(II) complexes.

The rate of autooxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in the presence of micelles formed from mixing equal concentrations of [Cu(C(12)-tmed)Br(2)] (where C(12)-tmed is N,N,N'-trimethyl-N'-dodecylethylenediamine) and several amino acids has been investigated. It was found that the rate in air-saturated solution is very much dependent on pH, which affects the availability of copper(II) coordination site for the catechol and the degree of micellization. At a given pH, the rates in [Cu(C(12)-tmed)Br(2)] micellar media are greatly enhanced in the presence sodium halide.

Synchronous fat plug myringoplasty and tympanostomy tube removal in the management of refractory otorrhoea in younger patients.

OBJECTIVE: Tympanostomy tubes are associated with many complications, the most common being recurrent otorrhoea, in many cases resistant to medical treatment. With the associated vestibulo-cochlear toxicity of many topical antibiotics, their use is dose limited. Removal of the tympanostomy tube has been shown to cure the otorrhoea, however, it is associated with a high persistent perforation rate of 10-28%. A synchronous fat plug myringoplasty was performed with tube removal in an attempt to reduce the residual perforation rate. METHODS: A retrospective study of 13 consecutive children, nine male and four female, mean age 9.1 years (median=9, range 2-15), with a total of 15 ears (left=6, right=9) had either Shah Tubes (n=5), Shepard Tubes (n=1) or Shah Long Term Tubes (n=9) in-situ for middle ear effusions. The tubes were removed for recurrent otorrhoea. The tubes had been in-situ for a mean of 38.8 months (median=31, range 9-84 months). All ears had recurrent infections, with a variable response to topical antibiotics. All were under the care of one specialist, who performed all the procedures. At the time of tube removal, a standard fat graft myringoplasty was done. RESULTS: The procedure was successful in 15 of the 15 ears, and all perforations had closed by 3 weeks. Pure tone audiometry improved in 11 ears, remained the same in two and worsened in two (0-10 and 11-15 dBA, respectively). There were no complications arising from the procedure. Mean follow up was 13.7 months (median=9, range 3-31). None of the patients have re-perforated, but two have required re-ventilation of their middle ear for middle effusions, and one of these two has also undergone subsequent adeno-tonsillectomy. CONCLUSIONS: Our experience in this small series shows that the removal of a tympanostomy tube for recurrent otorrhoea can be successfully managed with a fat plug myringoplasty, with the benefit of a reduction in the persistent perforation rate following tympanostomy tube removal. It is a simple technique that requires little extra operating time with no significant morbidity.

Prevalence of prostatitis-like symptoms in Singapore: a population-based study.

OBJECTIVE: To study the prevalence of prostatitis-like symptoms in a generally healthy population. SUBJECTS AND METHODS: A population-based cross-sectional survey was conducted in Singapore to evaluate "prostatitis-like symptoms" (PS), lower urinary tract symptoms (LUTS),erectile dysfunction (ED), and quality of life (QoL). Respondents with pain or discomfort in the perineum, testicles, tip of penis or bladder/suprapubic region were identified as having prostatitis-like symptoms. RESULTS: Altogether, 1087 males aged 21 to 70 were evaluated. While at least 20% of them had some degree of LUTS, only 2.67% (29 out of 1087) had pain or discomfort suggestive of prostatitis. Six men had pain in the bladder or suprapubic region, two in the perineum, six at the tip of penis and 26 had pain during micturition (11 subjects had more than one location of pain). Only two men had severe pain while seven had moderate and the rest had mild pain. The mean age of subjects with PS was 43.14. In terms of racial distribution, 2.23% (18) of Chinese, 3.15% (4) of Malay, 4.49% (4) of Indians and 12.12% (3) of other ethnic origin had PS. Those who had PS had worse erectile function (International Index of Erectile Function (IIEF) 11.92 vs. 17.16, p < 0.003) and a worse QoL score (2.96 vs. 1.38, p < 0.001) than those without PS. Those with PS were more bothered and worried about their symptoms. CONCLUSION: The prevalence of prostatitis-like symptoms in a largely Chinese population is 2.67%. Prostatitis-like symptoms have a negative impact on the quality of life and erectile function.

Erectile dysfunction in Singapore: prevalence and its associated factors--a population-based study.

PURPOSE: To study the prevalence of erectile dysfunction (ED) in Singapore males aged 30 and above and its association with demographic, medical and other risk factors. METHODOLOGY: A population based cross sectional study of 729 men aged 30 and above in Singapore was conducted using the abridged, five-item version of the International Index of Erectile Function (IIEF-5). Presence of erectile dysfunction was defined as IIEF-5 score of less than 21. Erectile dysfunction was further categorised into mild (IIEF-5: 16-20), moderate (IIEF-5: 11-15) and severe (IIEF-5: <11). A logistic regression model was used to identify significant independent risk factors for ED. RESULTS: Overall, 51.3% of respondents (n=374) reported some degree of erectile dysfunction. Of these, 23.2% have mild ED, 8.8% have moderate ED and 19.3% had severe ED. The prevalence of ED increased from 42.8% for men in their forties to 77.4% in their sixties. The prevalence of severe ED increased from 9.1% in men in their forties to 43.5% in their sixties and 77.0% in those aged 70 and above. Age above 50 years is the single most significant risk factor on multivariate analysis when adjusted for all confounding factors. Other important risk factors include Indian ethnic group, lower household income, physical inactivity, diabetes mellitus and cardiac diseases. CONCLUSION: Erectile dysfunction is common amongst Singaporean men. Age is the single most important physiologic factor affecting erectile function. The prevalence and severity increased significantly with age after 50 years old. With an ageing population, erectile dysfunction may become a significant health problem. Health care providers should plan their resources accordingly.

Detection of antibodies in cats infected with filarial parasites by the indirect immunofluorescence technique.

The indirect immunofluorescence technique in cats infected with filarial parasites, Brugia malayi, B. pahangi and D. repens were studied. The antibody level in infected microfilaraemic cats was higher than that in infected amicrofilaraemic cats and uninfected cats. Papain-treated whole microfilariae appeared to be more sensitive than the sonicated antigen. The comparative IFA titres using papain-treated and sonicated microfilarial antigen, in the serodiagnosis of filariasis is presented.

Experimental transplantation of limbs.

This article is a brief review of experimental and clinical studies on replantation and transplantation of the whole limbs. Special reference is given to our preliminary study of the foetal limb allograft in young rabbits. The results showed that the vascularised foetal limb allografts of the group with Cyclosporine A (CsA) treatment increased in longitudinal growth in their first 6 weeks of transplantation as compared to the group without CsA treatment. Transplantation of foetal tissue has yielded new possibilities in the treatment of congenital and traumatic limb defects in human in the future. The utility of foetal limb tissues brings us a step closer towards the long road of limb transplantation.

Oogenesis, fertilisation and early embryonic development in rats. I: Dose-dependent effects of pregnant mare serum gonadotrophins.

Five hundred and eight mature female Wistar rats divided into 35 different groups were stimulated with pregnant mare serum gonadotrophins (PMSG) (0, 5, 10, 20 & 40 IU) at the late diestrus stage to induce multiple follicular development. No chorionic gonadotrophin (CG) was used for ovulation induction. The quality of oocytes and their in vitro fertilisability, quality of Day 2-embryos, viability of pregnancy and status of fetuses on Day 14 of gestation and status of embryos retrieved on Day 2, 3, 4 and 5 of pregnancy in different subgroups of rats were examined. Results showed that more oocytes and embryos fertilised in in vivo were retrieved from rats supraphysiologically stimulated with 20 IU of PMSG. However, concurrent with the larger number, higher proportions of abnormal oocytes and embryos were found. High doses of PMSG caused lower in vitro fertilisability of oocytes and greater degrees of embryonic degeneration. Although, the number of oocytes and Day 2-embryos were higher in the 20PMGS dose group, the pregnancy rate was significantly reduced to 27%. In the 40PMSG group no viable pregnancy was noted. Most embryo demise occurred by day 3-5 of pregnancy, probably within the oviducts and before the implantation stage. In rats supraphysiologically stimulated with 20 and 40 IU of PMSG, the number of morphologically normal looking embryos was greatly reduced by Day 3-5 of pregnancy. In the 40PMSG group, there were no embryos retrieved by Day 4 and 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Oogenesis, fertilisation and early embryonic development in rats. II: Dose-dependent effects of human chorionic gonadotrophin.

A total of 950 female Wistar rats in 81 groups were involved in this study. Different groups of rats were stimulated with PMSG (0, 10 & 20 IU) at diestrus followed, 48-52 hr later, by different doses of HCG (0, 10, 20, 30 & 40) for ovulation induction. The dose-dependent effects of HCG, either with or without the use of PMSG for stimulation of multiple follicular development, on the quality of oocytes and their in vitro fertilisability, quality of Day 2-embryos, viability of pregnancy and status of embryos retrieved on Day 2, 3, 4 or 5 of pregnancy in different subgroups of rats were examined. Results showed that more oocytes and embryos fertilised in vivo were retrieved from rats supraphysiologically stimulated with 20 IU of PMSG. The addition of HCG did not increase the number of ovulated oocytes or Day-2 embryos. In other words, the number of oocytes or embryos produced is dependent on the dose of PMSG administered during diestrus rather than on the dose of HCG given for ovulation induction. Hence, no increase in the amount of HCG is required to effectively ovulate bigger cohort of preovulatory follicles in supraphysiologically stimulated rats. As was shown earlier, in vitro and in vivo fertilisation rates were reduced when higher doses of PMSG were used. Similarly, these rates were reduced when increasing doses of HCG were used in rats not previously stimulated with PMSG. When higher doses of HCG were used in rats stimulated earlier with PMSG (10 and 20 IU), the in vitro but not the in vivo fertilisation rates were further reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Laparoscopic telesurgery between the United States and Singapore.

INTRODUCTION: Telemedicine is the use of electronic digital signals to transfer information from one site to another. With the advent of a telepresence operative system and development of remote robotic arms to hold and manoeuvre the laparoscope, telemedicine is finding its role in surgery, especially laparoscopic surgery. CLINICAL FEATURES AND TREATMENT: We report two successful cases of laparoscopic surgery--radical nephrectomy and varicocelectomy for a 3-cm renal tumour and for bilateral varicoceles causing pain, where a less experienced laparoscopic surgeon in Singapore was telementored by an experienced laparoscopic surgeon located remotely in the United States. Both patients recovered uneventfully and returned home on postoperative day 4 and on the day of surgery, respectively. OUTCOME: This study demonstrates that telementored laparoscopic systems are feasible and safe, between countries halfway across the world. CONCLUSIONS: As the Internet expands in utility and the cost of higher bandwidth telecommunication lines decreases, even to remote countries, telementoring systems will become more affordable and may potentially pave the way for advanced surgical and laparoscopic applications and training for the future.

Endovascular coiling of a mycotic external carotid artery pseudoaneurysm following pharyngolaryngectomy with a free jejunal graft.

OBJECTIVES: (1) To highlight the significance of carotid artery pseudoaneurysm as a rare complication following neck dissection, and (2) to suggest endovascular coiling as management, in the presence of infection, previous radiotherapy and a grafted blood supply. CASE REPORT: A 66-year-old man diagnosed with squamous cell carcinoma of the hypopharynx and upper oesophagus underwent pharyngolaryngectomy with reconstruction of a neo-pharynx using a free jejunal graft. The patient had previously received radiotherapy for a soft palate squamous cell carcinoma. Two months after surgery, computed tomography demonstrated a bilobed pseudoaneurysm of the left external carotid artery just distal to the arterial branch supplying the jejunal graft. This mycotic pseudoaneurysm was successfully treated with endovascular coiling, while maintaining the patency of the superior thyroid artery supplying the jejunal graft anastomosis. CONCLUSION: In this patient, endovascular coiling of the external carotid artery was considered to be the only definitive treatment for a life-threatening mycotic pseudoaneurysm.