Publications by authors named "Hilditch T"

A refined numerical model for the evaporation and transport of droplets of binary solutions is introduced. Benchmarking is performed against other models found in the literature and experimental measurements of both electrodynamically trapped and freefalling droplets. The model presented represents the microphysical behavior of solutions droplets in the continuum and transition regimes, accounting for the unique hygroscopic behavior of different solutions, including the Fuchs-Sutugin and Cunningham slip correction factors, and accounting for the Kelvin effect.

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Understanding the factors that influence the airborne survival of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosols is important for identifying routes of transmission and the value of various mitigation strategies for preventing transmission. We present measurements of the stability of SARS-CoV-2 in aerosol droplets (∼5 to 10 µm equilibrated radius) over timescales spanning 5 s to 20 min using an instrument to probe survival in a small population of droplets (typically 5 to 10) containing ∼1 virus/droplet. Measurements of airborne infectivity change are coupled with a detailed physicochemical analysis of the airborne droplets containing the virus.

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Mono- and double-layer porous scaffolds were successfully fabricated using ball-milled agglomerates of Ti and Ti-10Nb-3Mo alloy. For selectively controlling the level of porosity and pore size, the agglomerates were sieved into two different size fractions of 100-300μm and 300-500μm. Compressive mechanical properties were measured on a series of cylindrical sintered compacts with different ratios of solid core diameter to porous layer width.

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Alzheimer's disease (AD) is an irreversible neurodegenerative disease that is characterised by the presence of β-amyloid (Aβ) plaques, neurofibrillary tangles (NFTs) and synaptic loss specifically in brain regions involved in learning and memory such as the neocortex and the hippocampus. Aβ depositions in the form of neuritic plaques trigger activation of microglia that is believed to be a common neuropathological feature of AD brains. As an integral part of the hippocampus, the dentate gyrus (DG) plays an important role in cognitive function.

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Background: Low-dose hormone replacement therapy (HRT) has attracted interest for the treatment of postmenopausal symptoms in diabetes because of concerns about increased risk of coronary heart disease (CHD) and stroke with conventional HRT containing conjugated equine oestrogens (CEEs) and medroxyprogesterone acetate (MPA).

Objectives: We assessed the effects on glucose homeostasis and cardiovascular risk factors of continuous oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with type 2 diabetes.

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We report the use of broth simulation as a means of validating the practice of sub-dispensing from stock vials of long-lived sterile radiopharmaceuticals. 'Matched' vials of nutrient broth accompanied the stock vials of long-lived sterile radiopharmaceuticals during their time in use and were subject to the same handling and storage procedures. At the end of the life of each radiopharmaceutical stock vial, the matching broth residue was sent for incubation and reporting.

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Background And Purpose: Blood pressure reduction is central to secondary prevention after stroke, but the optimal time to start therapy is unknown. Cerebral autoregulation is impaired early after ischaemic insult, and any changes in systemic blood pressure may be reflected in cerebral perfusion. However, early initiation in hospital may better assure continued long-term treatment.

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Background: Secondary prevention of stroke with antihypertensive drugs is now standard practice, but it is unclear how soon after a cerebrovascular event antihypertensive therapy should be initiated or re-started. Due to impaired cerebral autoregulation, changes in systemic blood pressure may be reflected in cerebral perfusion, especially in hypertensive patients immediately post-stroke. Conversely, early initiation in hospital may better assure continued long-term treatment.

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Twenty-six patients who had undergone recent surgery for differentiated thyroid cancer were investigated using iodine-131 iodide (120 MBq). Uptake in the thyroid bed was measured at 3 days using a dual-head gamma camera. An ablation activity of 131I iodide (4,000 MBq) was administered 3-38 (median 14) days later and uptake in the thyroid bed measured once or twice, 1-3 days post therapy.

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Technetium-99m (99Tc(m))-tetrofosmin was prepared using four different reconstitution methods. The radiochemical purity (RCP) of these products was assessed 8 h later using thin layer chromatography (TLC). Material produced using the original method supplied by the manufacturer and using an newer method, which involves the use of a vent needle and the addition of air, had acceptable RCP (mean +/- SD 94.

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Radiation doses to both the fingertip and finger base of staff preparing radiopharmaceuticals in a radionuclide dispensary have been monitored for more than 5 years. The records show a fall in dose thought to be due, largely, to the introduction of all-glass (lead) syringe shields. In 1998, the annual radiation dose (mean +/- standard deviation) to the fingertip had fallen to 83+/-11 mSv, which corresponded to 0.

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Radioiodinated meta-iodobenzylguanidine (MIBG) is used routinely for imaging and targeted radiotherapy of tumours derived from the neural crest. Since active uptake of MIBG by the noradrenaline transporter (NAT) makes a greater contribution to total drug accumulation than passive uptake when MIBG is present at low concentrations, tumour-specific uptake should be enhanced by the administration of lower molar amounts of MIBG. This could be achieved through the use of MIBG with a high specific activity.

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The radiochemical purity (RCP) of 99Tcm-MAG3 was determined using solid-phase extraction (SPE), high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). The difference between the HPLC and SPE methods was highly significant (P < 0.001), yielding values for RCP of 94.

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A gamma extremity monitoring system (GEMS) has been used to measure finger doses during radio-nuclide dispensing procedures. GEMS uses a small semi-conductor probe that can be attached to a finger from which a continuous read-out can be obtained that is related to dose rate. The pattern of dose accumulation can be analysed to allow doses received from individual operations within a procedure to be evaluated.

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PK1 comprises doxorubicin covalently bound to N-(2-hydroxypropyl)methacrylamide copolymer by a peptidyl linker. Following cellular uptake via pinocytosis, the linker is cleaved by lysosomal enzymes, allowing intratumoral drug release. Radically altered plasma and tumor pharmacokinetics, compared to free doxorubicin, and significant activity in animal tumors have been demonstrated preclinically.

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Background: The eradication of Helicobacter pylori infection is beneficial in patients with gastric or duodenal ulcers. The value of eradicating the infection in patients with dyspepsia and no evidence of ulcer disease is not known.

Methods: We performed a randomized, placebo-controlled trial comparing the efficacy of treatment for two weeks with 20 mg of omeprazole orally twice daily, 500 mg of amoxicillin three times daily (with 500 mg of tetracycline three times daily substituted for amoxicillin in patients allergic to penicillin), and 400 mg of metronidazole three times daily (160 patients) with that of omeprazole alone (158 patients) for resolving symptoms of dyspepsia in patients with H.

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Background: There are increasing indications for assessing Helicobacter pylori status by non-invasive means in dyspeptic patients. There is also increasing use of proton pump inhibitor therapy for dyspeptic disease.

Aims: To determine the effect of proton pump inhibitor therapy on the accuracy of the [14C]urea breath test.

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Background: Helicobacter pylori eradication therapy is routinely used for treating patients with peptic ulcer disease.

Aims: To assess the value of symptomatic response to H pylori eradication therapy as a marker of post-treatment H pylori status.

Patients And Methods: One hundred and nine dyspeptic patients with active duodenal or gastric ulceration association with H pylori infection had their symptoms measured by a validated questionnaire before and three months following H pylori eradication therapy.

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Article Synopsis
  • Dietary sodium restriction activates the renin-angiotensin system, which has effects on metabolism and could impact diabetes management.
  • A study involving eight patients with noninsulin-dependent diabetes mellitus (NIDDM) showed that a low-sodium diet (40 mmol/day) reduced insulin sensitivity by 12% compared to a high-sodium diet (160 mmol/day).
  • Blood pressure changes were minimal, suggesting that reduced sodium may affect insulin sensitivity more than cardiovascular function in these patients.
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Objective: Noninvasive tests for Helicobacter pylori are used increasingly. Our aim was to compare the Helisal Rapid Blood (HRB) test and 14C-urea breath test (UBT) for determining H. pylori status and predicting ulcer disease.

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A new gamma extremity monitoring system (GEMS) was used to assess finger doses of staff working in a hospital radionuclide dispensary. The system is designed to give a continuous readout of dose rate from a small probe which may be attached to a finger. It allows the contributions to radiation dose to the fingers from different parts of a procedure to be measured for the first time and the detailed pattern of radiation exposure to be determined.

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Background: There is interest in noninvasive H pylori testing as a means of predicting diagnosis and determining management in dyspeptic patients.

Aims: To assess the value of the 14C urea breath test as a predictor of peptic ulcer disease in patients presenting with dyspepsia.

Patients And Methods: 327 consecutive patients referred for investigation of dyspepsia had a 14C urea breath test performed before endoscopy.

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