Failure of non-vacuum steam sterilization processes for dental handpieces

Background: Dental handpieces are used in critical and semi-critical operative interventions. Although a number of dental professional bodies recommend that dental handpieces are sterilized between patient use there is a lack of clarity and understanding of the effectiveness of different steam sterilization processes. The internal mechanisms of dental handpieces contain narrow lumens (0·8-2·3mm) which can impede the removal of air and ingress of saturated steam required to achieve sterilization conditions. Aim: To identify the extent of sterilization failure in dental handpieces using a non-vacuum process. Methods: In-vitro and in-vivo investigations were conducted on commonly used UK benchtop steam sterilizers and three different types of dental handpieces. The sterilization process was monitored inside the lumens of dental handpieces using thermometric (TM) methods (dataloggers), chemical indicators (CI) and biological indicators (BI). Findings: All three methods of assessing achievement of sterility within dental handpieces that had been exposed to non-vacuum sterilization conditions demonstrated a significant number of failures (CI=8/3,024(fails/n tests); BI=15/3,024; TM=56/56) compared to vacuum sterilization conditions (CI=2/1,944; BI=0/1,944; TM=0/36). The dental handpiece most likely to fail sterilization in the non-vacuum process was the surgical handpiece. Non-vacuum sterilizers located in general dental practice had a higher rate of sterilization failure (CI=25/1,620; BI=32/1,620; TM=56/56) with no failures in vacuum process. Conclusion: Non-vacuum downward/gravity displacement, type-N steam sterilizers are an unreliable method for sterilization of dental handpieces in general dental practice. The handpiece most likely to fail sterilization is the type most frequently used for surgical interventions

Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes

Background: Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices, are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organisations still advocate non-vacuum sterilization processes for these devices. Aim: To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations. Methods: Measurements at different positions within air turbines were undertaken with thermocouples and dataloggers. Two examples of commonly used UK benchtop steam sterilizers were tested; a non-vacuum benchtop sterilizer (Little Sister 3, Eschmann, UK) and a vacuum benchtop sterilizer (Lisa, W&H, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate. Findings: A total of 140 measurements inside dental handpiece lumens were recorded. We demonstrate that the non-vacuum process fails (time range 0-150 seconds) to reliably achieve sterilization temperatures within the time limit specified by the International standard (15 seconds equilibration time). The measurement point at the base of the handpiece failed in all test runs (n=9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases. Conclusion: Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces and the base of the handpiece is the site most likely to fail

It’s gender Jim, but not as we know it … A critical review of constructions of gendered knowledge of the global south

This article explores how research helps construct a certain type of ‘gender’ knowledge that arises from, informs and reinforces ‘instrumentalist’ gendered policy perspectives on development of the Global South. It uses a case study of research funded under the ESRC-DFID Joint Fund for Poverty Alleviation which awarded 122 grants amounting to £66.2 million (around US$88 million) between 2005 and 2015. From a systematic review of the awards a typology of gender inclusion and exclusion was constructed that found 60% of all awards mentioned gender or included some level of gender analysis. The subsequent synthesis of the evidence suggested that in only 30% of all awards was the gendered knowledge produced central to the study and/or focused on better understanding gender roles, relations and identities. Applying a Feminist Institutionalist lens, the study highlights how institutional ideas around gender are reflected in the funding call specifications, and in turn influence how researchers ‘engendered’ their research, and the type of gendered knowledge produced. It finds much of the new gendered knowledge produced out of the Joint Fund emerged from non-gender focused research often produced by non-gendered researchers. It suggests that as gender becomes mainstreamed into research, and as more researchers ‘do gender’, so research becomes, conversely, less ‘gendered’. The ‘new’ gender knowledge produced may then merely evidence existing institutional policy positions rather than advance the policy agenda

Is there a patent troll problem in the UK?

This paper reports the findings of an empirical study of patent suits involving non-practicing entities (NPEs) in the U.K. between 2000 and 2010. Overall, we find that NPEs are responsible for 11% of all patent suits filed in the U.K. during this period. Though this is a small percentage by U.S. standards, our study suggests that patent trolling might not be as uniquely American as conventional wisdom suggests. We also find little support for many common explanations for Europe’s relative scarcity of NPE activity. For example, we find that NPEs litigating in the U.K. overwhelmingly assert high-tech patents – even more so, in fact, than their U.S. counterparts – despite higher barriers to software patentability in Europe. Our study does, however, tend to support fee-shifting as a key reason for the U.K.’s immunity to NPEs. We see evidence that the U.K.’s loser-pays legal regime deters NPEs from filing suit, while at the same time encouraging accused infringers to defend claims filed against them. U.K. NPE suits are initiated by potential infringers more often than by NPEs; rarely end in settlement; very rarely end in victory for NPEs; and, thus, result in an attorney’s fee award to the potential infringer more often than a damages award or settlement payment to the patentee. Together, these findings tend to support patent reform bills pending in the U.S. that would implement a fee-shifting regime for patent suits, and may also serve to lessen concerns that Europe’s forthcoming Unified Patent Court will draw NPEs to Europe

The Effect of Fee Shifting on Litigation: Evidence from a Court Reform in the UK

We study a U.K. court reform that established a cap on the amount of costs that a successful litigant may recover in a case litigated in the Patents County Court (PCC, now the IP Enterprise Court). We first build a theoretical model showing that the introduction of a costs cap is equivalent to an intermediate cost allocation rule falling between the English and American Rules. Our model suggests that the impact of the introduction of such a fee-shifting rule on the number of claims filed and the settlement rate is ambiguous. It shows, however, that the effect of the costs cap on IP holders' incentives to file a claim is stronger for smaller IP holders. Our empirical analysis of the impact of the costs cap takes advantage of our ability to compare IP litigation in the PCC with IP litigation in the High Court of England and Wales, which was not directly affected by the reform. Contrary to the existing literature, we find that the costs cap increased the number of cases filed by smaller companies and decreased the rate of settlement

Predicting melting points of organic molecules : applications to aqueous solubility prediction using the General Solubility Equation

In this work we make predictions of several important molecular properties of academic and industrial importance to seek answers to two questions: 1) Can we apply efficient machine learning techniques, using inexpensive descriptors, to predict melting points to a reasonable level of accuracy? 2) Can values of this level of accuracy be usefully applied to predicting aqueous solubility? We present predictions of melting points made by several novel machine learning models, previously applied to solubility prediction. Additionally, we make predictions of solubility via the General Solubility Equation (GSE) and monitor the impact of varying the logP prediction model (AlogP and XlogP) on the GSE. We note that the machine learning models presented, using a modest number of 2D descriptors, can make melting point predictions in line with the current state of the art prediction methods (RMSE ≥ 40 oC). We also find that predicted melting points, with an RMSE of tens of degrees Celsius, can be usefully applied to the GSE to yield accurate solubility predictions (log10S RMSE < 1) over a small dataset of druglike molecules.PostprintPostprintPeer reviewe

In-hospital worsening heart failure: a clinically relevant endpoint?

Outcome measures used for the clinical evaluation of patients with acute heart failure differ between studies and may neither adequately address the characteristic presenting symptoms and signs nor reflect the pathophysiological processes involved. In‐hospital worsening of heart failure (WHF) is associated with poor outcomes and thus a potential endpoint conveying clinically meaningful prognostic information.Current definitions of WHF are based on the combination of worsening symptoms and signs and the intensification of treatment during admission. Definitions vary across studies and do not fully account for baseline therapy or circumstances in which there is failure to respond to treatment. Further, there are limited data to inform healthcare professionals as to which patients are most at risk of developing in‐hospital WHF.In this opinion piece, we review the definitions for WHF used in recent and ongoing clinical trials and propose a novel definition, which captures failure to respond to treatment as well as clinical worsening (deterioration of symptoms and signs) of the patient's condition. Such a definition, applied consistently across studies, would help clarify the characteristics of patients likely to develop in‐hospital WHF, allow comparative assessments of the effectiveness of interventions, and help guide appropriate patient management in order to improve outcomes