Uncovering excellence in academic rankings: a closer look at the Shanghai ranking

In this paper, we examine whether the quality of academic research can be accurately captured by a single aggregated measure such as a ranking. With Shanghai University’s Academic Ranking of World Universities as the basis for our study, we use robust principal component analysis to uncover the underlying factors measured by this ranking. Based on a sample containing the top 150 ranked universities, we find evidence that, for the majority of these institutions, the Shanghai rankings reflect not one but in fact two different and uncorrelated aspects of academic research: overall research output and top-notch researchers. Consequently, the relative weight placed upon these two factors determines to a large extent the final ranking.     

Patent citation analysis.A closer look at the basic input data from patent search reports

The present paper focuses on some important requirements for understanding patent searchreports in view of their use for statistical analysis. It is pointed out and illustrated that thecomprehensiveness and the quality of a given search report may vary significantly as a function ofthe patent office drawing up the report. These differences imply consequences with respect to thesafe use and interpretation of the data. The authors stress that a sound analysis based on patentcitation data can only be performed in a meaningful way if the analyst has a minimum knowledgeof the underlying search reports.     

Intermittent pneumatic compression in patients with ESRD. A systematic review

Introduction: Patients with end‐stage renal disease (ESRD) experience frequent hemodialysis (HD) complications. Intradialytic hypotension (IDH) is a common complication presenting in approximately between 20 and 50% of HD sessions. Available interventions such as volume replacement or vasoactive medications are associated with significant side effects. Intermittent pneumatic compression (IPC) has been proposed as a feasible intervention for the prevention of IDH, treatment of peripheral arterial disease and venous ulcers. These devices apply intermittent pressure to the legs improving arterial blood flow, mobilization of pooled blood with an increase in venous return increasing the effective circulatory volume. Our goal was to identify the published clinical evidence on whether IPC has a circulatory benefit and is it well‐tolerated among patients receiving HD. Methods: We conducted a systematic review to identify studies assessing the efficacy and safety of IPC in patients with ESRD. Our primary outcome was IDH. Secondary outcomes such as HD comfort, ultrafiltration volume, and physical activity were collected. No restrictions where used and we included all observational and interventional studies. Two reviewers performed screening and study quality assessment. Findings: We included seven studies. Out of the seven studies, five addressed IDH, and the rest were included for secondary outcomes such as physical capacity and HD comfort. In one randomized crossover trial comparing exercise against IPC, 21 patients were randomized to 3 different arms (no intervention, cycling, IPC) a decrease in the rates of IDH with IPC was described (43%, 38%, and 24% respectively P = 0.014). The smaller studies corroborated these results. All studies where at high risk of bias. Discussion: IPC might offer significant benefits for patients undergoing HD not limited to prevention of IDH but also improvement of hemodialysis comfort and physical capacity. However, our results should be interpreted in the context of its limitations.     

Global ESRD Costs Associated with a Short Daily Hemodialysis Program in the United States

In spite of the growing evidence that daily hemodialysis (DHD) improves clinical outcomes and quality of life, the additional dialysis costs are not currently reimbursed in the United States. Nor have there been reports of the effects of DHD on end-stage renal disease (ESRD) global costs, which would help predict the financial impact of DHD on the ESRD program. Since 1996, 22 patients (20 in-center, 2 home) have switched from conventional thrice-weekly dialysis to short, daily dialysis with six treatments per week. Eighteen patients started for medical indications, and four started for nonmedical reasons. Causes of ESRD were the following: diabetes mellitus (6), hypertension (4), glomerulonephritis (6), hereditary (2), and other (4). Mean age was 56 ± 16 years. Patients had an average of 3.3 major comorbidities. Weekly conventional HD dialysis times were divided into six DHD treatments, each 2.0 ± 0.3 hours. Weekly Kt/V remained unchanged. Twenty-two patients were followed on DHD for 220 patient-months: 7 patients died after 1.8 ± 1.3 months, 2 were transplanted at 4.3 ± 3.2 months, and 2 discontinued DHD at 3.6 ± 4.8 months. Eleven patients remain on DHD at 17.4 ± 8.3 months. Actual costs per extra dialysis session are as follows: $14.30 for supplies and $3.20 for labor for setup/cleanup time (15 minutes at $12.80/hour). Annualized DHD savings are based on comparison of doses of epoetin alpha (Epogen) and blood pressure medication at the start and after 12 months of DHD. Hospitalization rates include all enrolled patients, comparing rates for the 12 months prior to DHD with the first year on DHD, or annualized rates for those on DHD less than one year. Cost assumptions are $9/ 1000 U Epogen, $1/blood pressure pill, and $1200/per day of hospitalization. Extra transportation costs were covered by the patients. No increased access problems were observed. For patients on short DHD longer than 12 months, supply and labor costs increased to $2733/patient/year; however, Epogen use was reduced 55%, and blood pressure medications were reduced 40%. For all patients who switched to DHD, hospitalization rates were reduced 24%. This resulted in a net savings of about $4241/patient/ year after 12 months on DHD. Overall ESRD costs were substantially decreased on DHD. These cost savings must be passed on to providers before DHD becomes more widely available.     

Primitive thermodynamics: A new look at the Clausius-Duhem inequality

New answers to an old question in a new context provide the basis for constructing a thermodynamics which is surprisingly simple and yet capable of modeling viscous fluids, viscoelastic bodies, elastic bodies, and heat conduction. The results obtain from a complete solution of the reduced dissipation inequality without considering functional dependences on histories. Constitutive relations are shown to take the form of a sum of two collections of terms; the first collection being the quasistatic part of classic thermodynamics, and the second is the dynamic part. This dynamic part consists of a gradient of a dissipation potential with respect to the dynamic variables and a collection of terms which gives an identically zero supply of entropy. Absolute minimia of the dissipation potential with respect to the dynamic variables are shown to be attained only in thermostatic states. The theory possesses a full system of symmetry relations and consistency with thermostatics is demonstrated.     

Outcomes of patients with end‐stage renal disease (ESRD) under chronic hemodialysis requiring continuous renal replacement therapy (CRRT) and patients without ESRD in acute kidney injury requiring CRRT: A single‐center study

In most continuous renal replacement therapy (CRRT) studies, end‐stage renal disease (ESRD) patients were excluded and the outcomes of patients with ESRD treated with chronic hemodialysis (HD) were unknown. The purposes of this study were to (1) evaluate short‐term patient survival and (2) compare the survival of conventional HD patients needing CRRT with the survival of non‐ ESRD patients in acute kidney injury (AKI) requiring CRRT. We evaluated adults (>18 years) requiring CRRT who were treated in the intensive care unit (ICU) at Kosin University Gospel Hospital from January 1, 2009 to December 31, 2010. A total of 100 (24 ESRD, 76 non‐ESRD) patients underwent CRRT during the study period. Patients were divided into two major groups: patients with ESRD requiring chronic dialysis and patients without ESRD (non‐ESRD) with AKI. We compared the survival of conventional HD patients requiring CRRT with the survival of non‐ ESRD patients in AKI requiring CRRT. For non‐ESRD patients, the 90‐day survival rate was 41.6%. For ESRD patients, the 90‐day survival rate was 55.3%. Multivariate Cox proportional hazards analyses demonstrated that conventional HD was not a significant predictor of mortality (hazard ratio [HR]: 0.334, 95% confidence interval [CI]: 0.063–1.763, P = 0.196), after adjustment for age, gender, presence of sepsis, APACHE score, use of vasoactive drugs, number of organ failures, ultrafiltration rate, and arterial pH. The survival rates of non‐ESRD and ESRD patients requiring CRRT did not differ; ESRD with conventional HD patients may be not a significant predictor of mortality.     

A look at the abundance of Chinese utility models

This article explores the multitude of Chinese utility model filings both from a statistical as well as from a legal standpoint. Both assignee and IPC analysis are used to gain insights into filing patterns and practices. A comparison of Chinese, German, and Japanese utility model laws show similarities and differences between the statutes and practices in these countries.     

Sex differences in vascular dysfunction and cardiovascular outcomes: The cardiac,endothelial function,and arterial stiffness in ESRD (CERES) study

Introduction: Recent studies suggest that women with end‐stage renal disease (ESRD) may have higher rates of mortality than men, but it is unknown whether sex differences in vascular function explain this disparity. The cardiac, endothelial function, and arterial stiffness in ESRD (CERES) study is an ongoing, prospective observational study designed to investigate vascular function, myocardial injury, and cardiovascular outcomes in ESRD. Methods: Among 200 CERES participants (34% women), we evaluated arterial wave reflections as augmentation index normalized to a heart rate of 75 (AIx75), arterial stiffness as pulse wave velocity, and macro‐ and microvascular endothelial dysfunction as flow‐mediated dilation and velocity time integral (VTI). Over a median of 14 months, participants were followed for the composite outcome of cardiovascular hospitalization or all‐cause death. Findings : Women had higher arterial wave reflection (Mean, SD AIx75 30% ± 9% for women vs. 21% ± 10% for men; P < 0.001) and worse microvascular function (VTI 55 ± 30 cm for women vs. 70 ± 27 cm for men; P = 0.007). After multivariable adjustment, female sex remained associated with a 0.5‐SD higher AIx75 (95% CI [0.01, 0.9]) and 0.3‐SD lower VTI (95%CI [0.1, 0.7]). Women experienced higher adjusted rates of the composite outcome (HR 2.5; 95%CI [1.1, 5.6]; P = 0.03), and further adjustment for arterial wave reflection attenuated this risk. Discussion: Vascular dysfunction may partly explain the association of female sex with higher cardiovascular risk and mortality in patients with ESRD. Further studies are needed to explore whether sex differences in vascular function predict long‐term outcomes, and whether hormonal or inflammatory factors explain these associations.     

A close look at valences in hexahedral element meshes

This paper discusses using valences in objective functions for topological modification of 3D hexahedral meshes. For topological optimization of 2D quadrilateral meshes, node valence (i.e. number of element edges attached to each node) is used to maximize the number of regular nodes (i.e. nodes with four attached edges). Difficulties in developing 3D hexahedral local topology modifications have limited the success of hexahedral topology optimization, although published literature suggests using an object function based on node valence. However, in this paper, we show that node valence is not a consistent measure of good hexahedral element topology, and objective functions based on node valence can lead to element topology, which will only admit concave element shapes. Instead, we propose that objective functions based on edge valence (i.e. number of quadrilateral faces attached to each element edge) will provide a consistent measure of element topology. Copyright © 2010 John Wiley & Sons, Ltd.     

Recent advances in CKD and ESRD: A literature update

The past year has seen interesting publications in the fields of chronic kidney disease and end stage renal disease. This review highlights some of these important papers and places their findings in the context of clinical care.     

A new look at the highT c superconductors using BCS-theory

Using the conventional phonon-exchange mechanism of superconductivity we have succeeded in reproducing the transition temperatureT _c of a large number of newly discovered highT _c superconductors by introducing a certain modification to the well-known BCS-formula forT _c .     

Teen driving in rural North Dakota: A qualitative look at parental perceptions

Motor vehicle crashes are the leading cause of death among teens in the United States. Graduated driver licensing (GDL) programs allow new drivers to gain driving experience while protecting them from high-risk situations. North Dakota was one of the last states to implement GDL, and the current program does not meet all of the best practice recommendations. This study used qualitative techniques to explore parents’ perceptions of the role teen driving plays in the daily lives of rural North Dakota families, their understanding of the risks faced by their novice teen drivers, and their support for GDL. A total of 28 interviews with parents of teens aged 13–16 years were conducted in four separate rural areas of the state. During the face-to-face interviews, parents described their teens’ daily lives as busy, filled with school, sports, and other activities that often required traveling considerable distances. Participation in school-sponsored sports and other school-related activities was highly valued. There was nearly unanimous support for licensing teens at age 14½, as was permitted by law at the time of the interviews. Parents expressed that they were comfortable supervising their teen's practice driving, and few reported using resources to assist them in this role. Although few parents expressed concerns over nighttime driving, most parents supported a nighttime driving restriction with exemptions for school, work or sports-related activities. Despite many parents expressing concern over distracted driving, there was less consistent support among parents for passenger restrictions, especially if there would be no exemptions for family members or school activities. These findings can assist in planning policies and programs to reduce crashes among novice, teen drivers, while taking into account the unique perspectives and lifestyles of families living in rural North Dakota.     

A new look at energy release rate in fracture mechanics

The energy balance for fracture in elastic/perfectly plastic solids is examined using the finite element method. An extension-release procedure that gives numerically converged solutions is employed in the numerical simulation of crack extensions in elastic/plastic solids. Increments of work and energy during crack extension are calculated for various loading conditions. Several conclusions are obtained. First, the elastic separation work of creating new crack surfaces is shown to be negligible, indicating that the Griffith-type energy release does not exist. Second, as the yield stress increases, the plastic dissipation work rate associated with crack extension converges to the energy release rate in the limiting elastic solid. The latter result can be adopted to interpret the classical energy release rate in elastic solids as plastic dissipation work rate taken in the limit as the yield stress approaches infinity during crack extension. Lastly, it is shown that the energy release rate obtained according to Irwin's plastic zone adjustment approach is equal to the plastic dissipation work rate for the original crack, provided the plastic zone size is less than 10% of the original crack size.     

We Should Strive for Optimal Hemodialysis: A Criticism of the Hemodialysis Adequacy Concept

Adequacy of hemodialysis is frequently equated with Kt/V_urea , the amount of urea clearance (K) multiplied by time (t) and divided by urea distribution volume (V). Several formulas have been developed to calculate Kt/V_urea from the pre‐ and post‐dialysis urea concentrations. In three‐times‐weekly hemodialysis, a single pool (spKt/V_urea) value of 1.3 per treatment is commonly considered to indicate adequate therapy.
Despite providing the recommended spKt/V_urea of 1.3 per treatment, short dialysis with rapid ultrafiltration is associated with multiple intradialytic and interdialytic complications. Patients experience cramps, nausea, vomiting, headaches, fatigue, hypotensive episodes during dialysis, and hangover after dialysis; patients remain fluid overloaded with subsequent poor blood pressure control, left ventricular hypertrophy, diastolic dysfunction, and high cardiovascular mortality.
According to Webster's dictionary, "optimal" means most desirable or satisfactory; "adequate" means sufficient for a specific requirement or barely sufficient or satisfactory. Optimal dialysis is the method of dialysis yielding results that cannot be further improved. New approaches, including hemeral quotidian or long nocturnal dialysis, provide opportunities to abandon the notion that adequate dialysis is "good enough" for our patients. Optimal dialysis should be our goal. Dialysis sessions should be long and frequent enough to provide excellent intra‐ and interdialytic tolerance of hemodialysis, normalization of serum calcium and phosphorus, blood pressure control, normal myocardial morphology and function, and hormonal balance, and to eliminate all, even subtle, uremic symptoms.     

Massive catheter‐related thrombosis of vena cava superior protruding into the right atrium in a hemodialysis patient

A 36‐year‐old man with chronic renal insufficiency secondary to type 1 diabetes mellitus was on hemodialysis via central venous catheter (CVC), newly placed into the right subclavian vein after his arteriovenous fistula became dysfunctional. Seven days after CVC insertion, the patient developed fever and on day 11 echocardiography showed a large nearly occluding thrombus in the superior vena cava (SVC) extending into the right atrium (RA). Emergency surgical thrombectomy was successfully performed and an 11 cm long thrombus extending from the RA cranially into the SVC occupying majority of the vein's lumen was removed. Cultures from the thrombus and CVC were negative, but polymerase chain reaction was positive for Staphylococcus aureus. This particular case was interesting for a marked discrepancy between large SVC occluding thrombosis and a relatively mild clinical presentation with fever, and it highlights the importance of correct timing of echocardiography exam which might prevent potentially fatal consequences such as pulmonary embolism.     

Left ventricular assist device patient maintained on home hemodialysis: A novel class of patients to the home dialysis population

Severe heart failure is increasingly being managed by cardiac transplantation, and in some cases mechanical support devices serve as destination therapies. Left ventricular assist devices (LVADs) were approved for destination therapy for end stage heart failure patients before the more advanced total artificial heart modality became available. One common complication of mechanical assist device placement is acute kidney injury. Historically, patients with mechanical support devices have had to have inpatient hemodialysis until combined heart kidney transplant. Though, some units have started accepting LVAD patients in outpatient dialysis clinics. The cost of in center hemodialysis remains high and home dialysis modalities are becoming increasingly popular. We report the first patient with an LVAD to undergo training and successful home hemodialysis while awaiting combined heart kidney transplantation.     

Sticking to the script: A curious case of confusion in an ESRD patient

A 60‐year‐old male Dialysis patient presented with altered mental status and Hypertensive Urgency. He had a significant lesion noted on his glans penis. He was treated for infection and hypertension with expectant management, without significant improvement in his mental acuity. Laboratory and radiologic workup were unrevealing for the etiology. Upon detailed review it was noted he had recently been given Acyclovir for a presumed Herpes Simplex Virus infection. He had been prescribed what is considered correct dosing for an ESRD patient. An Acyclovir level was obtained and urgent Dialysis was undertaken, presuming Acyclovir neurotoxicity may be the culprit. Initially no improvement was noted and a 2nd level and hemodialysis were undertaken. This case and review of the literature will highlight key aspects of acyclovir neurotoxicity in ESRD patients, including how to diagnose and treat, which laboratory tests to obtain and what one can expect from various dialysis modalities. We will also reveal how to dose Acyclovir to avoid toxicity and other key elements of the drug.     

A fresh look at the free flight dynamics of a spinning projectile

In the first part of the paper, several equations of motion by different groups of workers are critically examined. Exact equations of motion are then developed. This form is then quasi-linearised into a ballistic formulation. The geometrical motion of a spinning projectile, in the presence of a cubic restoring moment is analysed in the cross-flow plane. It is observed that the trajectories assume a cuspidal form at the lower and upper range of the travel, when the angular momentum parameter coincides with these points. In general, both steady and unsteady precessional motions are presented.