Complexes of Thiourea with alkali metal bromides and iodides: Structural properties, mixed-halide and mixed-metal materials, and halide exchange processes

We report the preparation and structural properties of complexes of metal halides and thiourea with composition MX[thiourea]4 (MX = KBr, KI, RbI, CsI), together with the mixed-halide materials KBrnI1–n[thiourea]4 (0 < n < 1) and the mixed-metal materials KnCs1–nI[thiourea]4 (0 < n < 1). These materials are isostructural, with a tetragonal structure (space group P4/mnc) characterized by M+[thiourea]4 coordination columns along the 4-fold axis and halide anions located in channels in the region of space between adjacent columns and running parallel to the columns. For the mixed-halide materials, the stoichiometry KBrnI1–n[thiourea]4 depends on the bromide/iodide ratio in the crystallization solution; the crystalline complexes have a higher bromide/iodide ratio than the crystallization solution, indicating preferential incorporation of bromide within the complex. Soaking crystals of KBr0.61I0.39[thiourea]4 in iodide containing solutions leads to halide exchange, with the iodide to bromide ratio increasing relative to the parent crystal. Further experiments produced no evidence that these thiourea complexes can accommodate extended polyiodide networks

V2I Applications in Highways: How RSU Dimensioning Can Improve Service Delivery

This paper investigates the performance of Vehicle-to-Infrastructure (V2I) services over Vehicular Networks (VANETs) that are assisted by Road Side Units (RSU). More specifically, an analytical study of RSU dimensioning and a respective module is designed and developed in a simulated VANET environment. Two V2I application scenarios (e.g. car crash, spot weather) are considered in order to evaluate the impact of RSUs, vehicles’ size and speed and car crash start time and duration on applications’ performance. It is shown that the VANET network metrics (Packet Loss and Packet Delivery Ratio) are affected by the available MAC Bit rates and application scenarios. Mobility model metrics (Total Busy Time and Total CO2 Emissions) are also affected by the different application scenarios, number and type of vehicles

Percutaneous ablation techniques for renal cell carcinoma: current status and future trends

Percutaneous ablation is an increasingly applied technique for the treatment of localized renal tumors, especially for elderly or co-morbid patients, where co-morbidities increase the risk of traditional nephrectomy. Ablative techniques are technically suited for the treatment of tumors generally not exceeding 4 cm, which has been set as general consensus cutoff and is described as the upper threshold of T1a kidney tumors. This threshold cutoff is being challenged, but with still limited evidence. Percutaneous ablation techniques for the treatment of renal cell carcinoma (RCC) include radiofrequency ablation, cryoablation, laser or microwave ablation; the main advantage of all these techniques over surgery is less invasiveness, lower complication rates and better patient tolerability. Currently, international guidelines recommend percutaneous ablation either as intervention for frail patients or as a first line tool, provided that the tumor can be radically ablated. The purpose of this article is to describe the basic concepts of percutaneous ablation in the treatment of RCC. Controversies concerning techniques and products and the need for patient-centered tailored approaches during selection among the different techniques available will be discussed

Longest common extensions with wildcards: trade-off and applications

We study the Longest Common Extension (LCE) problem in a string containing wildcards. Wildcards (also called "don't cares" or "holes") are special characters that match any other character in the alphabet, similar to the character "?" in Unix commands or "." in regular expression engines. We consider the problem parametrized by G, the number of maximal contiguous groups of wildcards in the input string. Our main contribution is a simple data structure for this problem that can be built in O(n (G/t) log n) time, occupies O(nG/t) space, and answers queries in O(t) time, for any t ∈ [1 .. G]. Up to the O(log n) factor, this interpolates smoothly between the data structure of Crochemore et al. [JDA 2015], which has O(nG) preprocessing time and space, and O(1) query time, and a simple solution based on the "kangaroo jumping" technique [Landau and Vishkin, STOC 1986], which has O(n) preprocessing time and space, and O(G) query time. By establishing a connection between this problem and Boolean matrix multiplication, we show that our solution is optimal up to subpolynomial factors when G = Ω(n) under a widely believed hypothesis. In addition, we develop a new simple, deterministic and combinatorial algorithm for sparse Boolean matrix multiplication. Finally, we show that our data structure can be used to obtain efficient algorithms for approximate pattern matching and structural analysis of strings with wildcards. First, we consider the problem of pattern matching with k errors (i.e., edit operations) in the setting where both the pattern and the text may contain wildcards. The "kangaroo jumping" technique can be adapted to yield an algorithm for this problem with runtime O(n(k+G)), where G is the total number of maximal contiguous groups of wildcards in the text and the pattern and n is the length of the text. By combining "kangaroo jumping" with a tailor-made data structure for LCE queries, Akutsu [IPL 1995] devised an O(n√{km} polylog m)-time algorithm. We improve on both algorithms when k ≪ G ≪ m by giving an algorithm with runtime O(n(k + √{Gk log n})). Secondly, we give O(n√G log n)-time and O(n)-space algorithms for computing the prefix array, as well as the quantum/deterministic border and period arrays of a string with wildcards. This is an improvement over the O(n√{nlog n})-time algorithms of Iliopoulos and Radoszewski [CPM 2016] when G = O(n / log n)

Internal pattern matching in small space and applications

In this work, we consider pattern matching variants in small space, that is, in the read-only setting, where we want to bound the space usage on top of storing the strings. Our main contribution is a space-time trade-off for the Internal Pattern Matching (IPM) problem, where the goal is to construct a data structure over a string S of length n that allows one to answer the following type of queries: Compute the occurrences of a fragment P of S inside another fragment T of S, provided that |T| < 2|P|. For any τ ∈ [1 . . n/log² n], we present a nearly-optimal Õ(n/τ)-size data structure that can be built in Õ(n) time using Õ(n/τ) extra space, and answers IPM queries in O(τ+log n log³ log n) time. IPM queries have been identified as a crucial primitive operation for the analysis of algorithms on strings. In particular, the complexities of several recent algorithms for approximate pattern matching are expressed with regards to the number of calls to a small set of primitive operations that include IPM queries; our data structure allows us to port these results to the small-space setting. We further showcase the applicability of our IPM data structure by using it to obtain space-time trade-offs for the longest common substring and circular pattern matching problems in the asymmetric streaming setting

Internal shortest absent word queries

Given a string T of length n over an alphabet Σ ⊂ {1, 2, . . . , nO(1)} of size σ, we are to preprocess T so that given a range [i, j], we can return a representation of a shortest string over Σ that is absent in the fragment T[i] · · · T[j] of T. For any positive integer k ∈ [1, log logσ n], we present an O((n/k) · log logσ n)-size data structure, which can be constructed in O(n logσ n) time, and answers queries in time O(log logσ k)

Improving survival of probiotic bacteria using bacterial poly-γ-glutamic acid

A major hurdle in producing a useful probiotic food product is bacterial survival during storage and ingestion. The aim of this study was to test the effect of γ-PGA immobilisation on the survival of probiotic bacteria when stored in acidic fruit juice. Fruit juices provide an alternative means of probiotic delivery, especially to lactose intolerant individuals. In addition, the survival of γ-PGA-immobilised cells in simulated gastric juice was also assessed. Bifidobacteria strains (B. longum, B. breve), immobilised on 2.5 % γ-PGA, survived significantly better (P < 0.05) in orange and pomegranate juice for 39 and 11 days respectively, compared to free cells. However, cells survived significantly better (P < 0.05) when stored in orange juice compared to pomegranate juice. Moreover, both strains, when protected with 2.5 % γ-PGA, survived in simulated gastric juice (pH 2.0) with a marginal reduction (<0.47 log CFU/ml) or no significant reduction in viable cells after four hours, whereas free cells died within two hours. In conclusion, this research indicates that γ-PGA can be used to protect Bifidobacteria cells in fruit juice, and could also help improve the survival of cells as they pass through the harsh conditions of the gastrointestinal tract (GIT). Following our previous report on the use of γ-PGA as a cryoprotectant for probiotic bacteria, this research further suggests that γ-PGA could be used to improve probiotic survival during the various stages of preparation, storage and ingestion of probiotic cells

Clinic variation in glycaemic control for children with Type 1 diabetes in England and Wales:a population-based, multilevel analysis

AIM: To understand the scope for improving children's glycaemic outcomes by reducing variation between clinics and examine the role of insulin regimen and clinic characteristics. METHODS: Cross-sectional analysis of 2012-2013 National Paediatric Diabetes Audit data from 21 773 children aged < 19 years with Type 1 diabetes cared for at 176 clinics organized into 11 regional diabetes networks in England and Wales. Variation in HbA1c was explored by multilevel models with a random effect for clinic. The impact of clinic context was quantified by computing the per cent of total variation in HbA1c which occurs between clinics (intraclass correlation coefficient; ICC). RESULTS: Overall, 69 of the 176 diabetes clinics (39%) had a glycaemic performance that differed significantly from the national average after adjusting for patient case-mix with respect to age, gender, diabetes duration, deprivation and ethnicity. However, differences between clinics accounted for 4.7% of the total variation in HbA1c . Inclusion of within-clinic HbA1c standard deviation led to a substantial reduction in ICC to 2.4%. Insulin regimen, clinic volume and diabetes networks had a small or moderate impact on ICC. CONCLUSIONS: Differences between diabetes clinics accounted for only a small portion of the total variation in glycaemic control because most of the variation was within clinics. This implies that national glycaemic improvements might best be achieved not only by targeting poor centres but also by shifting the whole distribution of clinics to higher levels of quality