bluuebunny/crossref_metadata_2025 huggingface dataset:
ESTABLISH A MECHANICAL DAMPING MODEL FOR EVALUATING THE SURROUNDING SOFT TISSUE OF DENTAL IMPLANT
Authors: HUANG CHING-HSUN , FAN KANG-HSIN , WU CHING-ZONG , HUANG HAW-MING
Published: April 2019

Multiple variables have been shown to influence early marginal bone loss around dental implants. Among these factors, the location of the microgap related to the alveolar crest, occlusion, crest module and soft tissue thickness were reported to be important factors for deciding the final outcome of the implant treatment. The purpose of this study was to establish a damping model to simulate the mechanical function of dental implants in the oral cavity. The experimental implant model consisted of a screw-type implant (10[Formula: see text]mm). The implant was placed into epoxy resin which was used to simulate bone tissue. In this study, two kinds of epoxy resin were used: PL-1 (with elastic moduli of 2900[Formula: see text]MPa) and PL-2 (210[Formula: see text]MPa) were used to simulate cortical bone and cancellous bone, respectively. Above bone block, a soft lining material was used to simulate the soft tissue around implant. In addition, two-implant model with various distance between implants were established to discuss the effect of soft tissue effect on the damping factors (DF) of the implant system. A noninvasive impulse-forced vibration technique was used to detect the damping factors of the implant models as previous reported. Briefly, the signal excitation was detected through the micro-phone and sent to the spectrum analyzer. The frequency response was obtained from a vibration-time histogram using Fast Fourier Transform software. The DF value of the signal dental implant model was detected to be [Formula: see text]. This value is closed to the in vivo data that was reported previously. This result showed that the model established in this study is a validated model for damping analysis. Furthermore, the DF value of a dental implant surrounded with 3[Formula: see text]mm soft tissue ([Formula: see text]) is significantly higher than the implant with 2[Formula: see text]mm-surround soft tissue ([Formula: see text]). In addition, implant models with larger interval distance between implants showed higher DF values. According to the results of this study, it is reasonable to suggest that dental implant surrounded with higher amount soft tissue may reduce more vibration amplitude while an occlusal force was applied to a dental implant. This vibration reducing effect may be helpful to reduce alveolar bone resorption around implants.
INVESTIGATION INTO WHETHER OR NOT PMMA BONE CEMENT TRANSPEDICULAR SCREW AUGMENTATION STABILIZES PEDICLE SCREW LOOSENING
Authors: LIU PO-YI , LIN SHENG-CHIH , LAI PO-LIANG , LIN CHUN-LI
Published: April 2019

Pedicle screw loosening at the bone–screw interface is the main complication in pedicle screw fixation. The transpedicular polymethylmethacrylate screw augmentation technique has recently become the general technique used to re-operatively overcome pedicle screw loosening. This study investigates the fatigue resistance of PMMA bone cement augmentation. Twenty-seven porcine thoracic vertebral bodies were collected. The BMD was measured using dual X-ray absorptiometry. Each vertebral body was instrumented with one pedicle screw and mounted in a material testing system. Fatigue testing was performed by implementing a cranio-caudal sinusoidal, cyclic (5[Formula: see text]Hz) load. This study shows that transpedicular pedicle screw augmentation with PMMA exhibits similar fatigue resistance as traditional pedicle screw implantation. However, in histomophometrical analysis, the transpedicular pedicle screw augmentation with PMMA has greater anti-deformation capacity than traditional pedicle screw implantation. Transpedicular pedicle screw augmentation with PMMA improves more screw holding power to prevent pedicle screw loosening.
Condition for zero and nonzero discord in graph Laplacian quantum states
Authors: Dutta Supriyo , Adhikari Bibhas , Banerjee Subhashish
Published: April 2019

This work is at the interface of graph theory and quantum mechanics. Quantum correlations epitomize the usefulness of quantum mechanics. Quantum discord is an interesting facet of bipartite quantum correlations. Earlier, it was shown that every combinatorial graph corresponds to quantum states whose characteristics are reflected in the structure of the underlined graph. A number of combinatorial relations between quantum discord and simple graphs were studied. To extend the scope of these studies, we need to generalize the earlier concepts applicable to simple graphs to weighted graphs, corresponding to a diverse class of quantum states. To this effect, we determine the class of quantum states whose density matrix representation can be derived from graph Laplacian matrices associated with a weighted directed graph and call them graph Laplacian quantum states. We find the graph theoretic conditions for zero and nonzero quantum discord for these states. We apply these results on some important pure two qubit states, as well as a number of mixed quantum states, such as the Werner, Isotropic, and [Formula: see text]-states. We also consider graph Laplacian states corresponding to simple graphs as a special case.
Femtosecond Laser-Assisted Synthesis of ZnO Nanoparticles in Solvent with Visible Emission for Temperature Sensing
Authors: Xu Huanhuan , Yan Lihe , Si Jinhai , Xu Yanmin , Hou Xun
Published: April 2019

Zinc oxide (ZnO) nanoparticles (NPs) are synthesized by one-step femtosecond laser ablation of zinc powders in n-methyl pyrrolidone (NMP) at room temperature. The as-prepared ZnO NPs are fairly stable, water-soluble and have abundant surface functional groups resulting in a strong fluorescence in the visible region. By further annealing the ZnO NPs in the reacting solvent up to 120∘C, the photoluminescence (PL) intensity of material can be significantly enhanced. Besides, the PL of ZnO NPs can change from blue to green by controlling the annealing temperature. The products exhibit excellent temperature sensing with high temperature sensitivity and a 1.3% change per∘C response over a linear temperature sensing range (6–84[Formula: see text] in aqueous buffer, which matches well with the physiologically relevant temperatures. Hence, the ZnO nanoparticle system can serve as a promising candidate for practical fluorescent temperatures nanosensors which can be used for accurate temperature monitoring within biological systems.
A setwise EWMA scheme for monitoring high-dimensional datastreams
Authors: Feng Long , Ren Haojie , Zou Changliang
Published: April 2019

The monitoring of high-dimensional data streams has become increasingly important for real-time detection of abnormal activities in many statistical process control (SPC) applications. Although the multivariate SPC has been extensively studied in the literature, the challenges associated with designing a practical monitoring scheme for high-dimensional processes when between-streams correlation exists are yet to be addressed well. Classical [Formula: see text]-test-based schemes do not work well because the contamination bias in estimating the covariance matrix grows rapidly with the increase of dimension. We propose a test statistic which is based on the “divide-and-conquer” strategy, and integrate this statistic into the multivariate exponentially weighted moving average charting scheme for Phase II process monitoring. The key idea is to calculate the [Formula: see text] statistics on low-dimensional sub-vectors and to combine them together. The proposed procedure is essentially distribution-free and computation efficient. The control limit is obtained through the asymptotic distribution of the test statistic under some mild conditions on the dependence structure of stream observations. Our asymptotic results also shed light on quantifying the size of a reference sample required. Both theoretical analysis and numerical results show that the proposed method is able to control the false alarm rate and deliver robust change detection.
A Dynamic Service Migration Mechanism in Edge Cognitive Computing
Authors: Chen Min , Li Wei , Fortino Giancarlo , Hao Yixue , Hu Long , Humar Iztok
Published: April 2019

Driven by the vision of edge computing and the success of rich cognitive services based on artificial intelligence, a new computing paradigm, edge cognitive computing (ECC), is a promising approach that applies cognitive computing at the edge of the network. ECC has the potential to provide the cognition of users and network environmental information, and further to provide elastic cognitive computing services to achieve a higher energy efficiency and a higher Quality of Experience (QoE) compared to edge computing. This article first introduces our architecture of the ECC and then describes its design issues in detail. Moreover, we propose an ECC-based dynamic service migration mechanism to provide insight into how cognitive computing is combined with edge computing. In order to evaluate the proposed mechanism, a practical platform for dynamic service migration is built up, where the services are migrated based on the behavioral cognition of a mobile user. The experimental results show that the proposed ECC architecture has ultra-low latency and a high user experience, while providing better service to the user, saving computing resources, and achieving a high energy efficiency.
XOR-Based Low-Cost Reconfigurable PUFs for IoT Security
Authors: Liu Weiqiang , Zhang Lei , Zhang Zhengran , Gu Chongyan , Wang Chenghua , O'neill Maire , Lombardi Fabrizio
Published: April 2019

With the rapid development of the Internet of Things (IoT), security has attracted considerable interest. Conventional security solutions that have been proposed for the Internet based on classical cryptography cannot be applied to IoT nodes as they are typically resource-constrained. A physical unclonable function (PUF) is a hardware-based security primitive and can be used to generate a key online or uniquely identify an integrated circuit (IC) by extracting its internal random differences using so-called challenge-response pairs (CRPs). It is regarded as a promising low-cost solution for IoT security. A logic reconfigurable PUF (RPUF) is highly efficient in terms of hardware cost. This article first presents a new classification for RPUFs, namely circuit-based RPUF (C-RPUF) and algorithm-based RPUF (A-RPUF); two Exclusive OR (XOR)-based RPUF circuits (an XOR-based reconfigurable bistable ring PUF (XRBR PUF) and an XOR-based reconfigurable ring oscillator PUF (XRRO PUF)) are proposed. Both the XRBR and XRRO PUFs are implemented on Xilinx Spartan-6 field-programmable gate arrays (FPGAs). The implementation results are compared with previous PUF designs and show good uniqueness and reliability. Compared to conventional PUF designs, the most significant advantage of the proposed designs is that they are highly efficient in terms of hardware cost. Moreover, the XRRO PUF is the most efficient design when compared with previous RPUFs. Also, both the proposed XRRO and XRBR PUFs require only 12.5% of the hardware resources of previous bitstable ring PUFs and reconfigurable RO PUFs, respectively, to generate a 1-bit response. This confirms that the proposed XRBR and XRRO PUFs are very efficient designs with good uniqueness and reliability.
Using Episodic Memory for User Authentication
Authors: Woo Simon S. , Artstein Ron , Kaiser Elsi , Le Xiao , Mirkovic Jelena
Published: April 2019

Passwords are widely used for user authentication, but they are often difficult for a user to recall, easily cracked by automated programs, and heavily reused. Security questions are also used for secondary authentication. They are more memorable than passwords, because the question serves as a hint to the user, but they are very easily guessed. We propose a new authentication mechanism, called “life-experience passwords (LEPs).” Sitting somewhere between passwords and security questions, an LEP consists of several facts about a user-chosen life event—such as a trip, a graduation, a wedding, and so on. At LEP creation, the system extracts these facts from the user’s input and transforms them into questions and answers. At authentication, the system prompts the user with questions and matches the answers with the stored ones. We show that question choice and design make LEPs much more secure than security questions and passwords, while the question-answer format promotes low password reuse and high recall.

Specifically, we find that: (1) LEPs are 10
9
--10
14
× stronger than an ideal, randomized, eight-character password; (2) LEPs are up to 3 × more memorable than passwords and on par with security questions; and (3) LEPs are reused half as often as passwords. While both LEPs and security questions use personal experiences for authentication, LEPs use several questions that are closely tailored to each user. This increases LEP security against guessing attacks. In our evaluation, only 0.7% of LEPs were guessed by casual friends, and 9.5% by family members or close friends—roughly half of the security question guessing rate. On the downside, LEPs take around 5 × longer to input than passwords. So, these qualities make LEPs suitable for multi-factor authentication at high-value servers, such as financial or sensitive work servers, where stronger authentication strength is needed.
Cashtag Piggybacking
Authors: Cresci Stefano , Lillo Fabrizio , Regoli Daniele , Tardelli Serena , Tesconi Maurizio
Published: April 2019

Microblogs are increasingly exploited for predicting prices and traded volumes of stocks in financial markets. However, it has been demonstrated that much of the content shared in microblogging platforms is created and publicized by bots and spammers. Yet, the presence (or lack thereof) and the impact of fake stock microblogs has never been systematically investigated before. Here, we study 9M tweets related to stocks of the five main financial markets in the US. By comparing tweets with financial data from Google Finance, we highlight important characteristics of Twitter stock microblogs. More importantly, we uncover a malicious practice—referred to as
cashtag piggybacking
—perpetrated by coordinated groups of bots and likely aimed at promoting low-value stocks by exploiting the popularity of high-value ones. Among the findings of our study is that as much as 71% of the authors of suspicious financial tweets are classified as bots by a state-of-the-art spambot-detection algorithm. Furthermore, 37% of them were suspended by Twitter a few months after our investigation. Our results call for the adoption of spam- and bot-detection techniques in all studies and applications that exploit user-generated content for predicting the stock market.
Tight Lower Bounds for the Complexity of Multicoloring
Authors: Bonamy Marthe , Kowalik łUkasz , Pilipczuk Michał , Socała Arkadiusz , Wrochna Marcin
Published: April 2019

In the
multicoloring
problem, also known as (
a
:
b
)-
coloring
or
b-fold coloring
, we are given a graph
G
and a set of
a
colors, and the task is to assign a subset of
b
colors to each vertex of
G
so that adjacent vertices receive disjoint color subsets. This natural generalization of the classic coloring problem (the
b
=1 case) is equivalent to finding a homomorphism to the Kneser graph
KG

a,b

and gives relaxations approaching the fractional chromatic number.

We study the complexity of determining whether a graph has an (
a
:
b
)-coloring. Our main result is that this problem does not admit an algorithm with runtime
f
(
b
)ċ 2

o
(log
b
)ċ
n

for any computable
f(b)
unless the Exponential Time Hypothesis (ETH) fails. A (
b
+1)

n

ċ poly(
n
)-time algorithm due to Nederlof [33] shows that this is tight. A direct corollary of our result is that the graph homomorphism problem does not admit a 2

O
(
n
+
h
)

algorithm unless the ETH fails even if the target graph is required to be a Kneser graph. This refines the understanding given by the recent lower bound of Cygan et al. [9].

The crucial ingredient in our hardness reduction is the usage of
detecting matrices
of Lindström [28], which is a combinatorial tool that, to the best of our knowledge, has not yet been used for proving complexity lower bounds. As a side result, we prove that the runtime of the algorithms of Abasi et al. [1] and of Gabizon et al. [14] for the
r
-monomial detection problem are optimal under the ETH.
Preeclampsia Induced Liver Dysfunction Complicated by Disseminated Intravascular Coagulopathy and Placental Abruption: A Case Report and Review of the Literature
Authors: Myers Jordan , Wu Gary , Shapiro Robert E. , Vallejo Manuel C.
Published: April 2019

A 33-year-old primigravida at 32-week gestation was admitted to labor and delivery complaining of severe right upper quadrant pain and worsening coagulopathy. We report the anesthetic and obstetrical management of a complex case of a parturient with a mixed picture of hemolysis, elevated liver enzymes and low platelets who was delivered under general anesthesia further complicated by Disseminated Intravascular Coagulopathy (DIC) and placental abruption.
Mass Transfer and Intrinsic Light Variability in the Contact Binary MT Cas
Authors: Dai Haifeng , Yuan Huiyu , Yang Yuangui
Published: April 2019

First CCD photometry for the contact binary MT Cas is performed in 2013 in December. The spectral type of F8V is determined from the low-precision spectrum observed on 2018 Oct 22. With Wilson-Devinney code, the photometric solutions are deduced from VRc light curves (LCs) and AAVSO’s and ASAS-SN’s data, respectively. The results imply that MT Cas is a W-type weak-contact binary with a mass ratio of q=2.365(±0.005) and a fill-out factor of f=16.6(±1.2)%, respectively. The asymmetric LCs in 2013 are modeled by a dark spot on the more massive component. By analyzing the (O-C) curve, it is discovered that the orbital period may be undergoing a secular increase at a rate of dP/dt=1.12(±0.09)×10-8d  yr-1, which may result from mass transfer from the less massive component to the more massive one. With mass transferring, MT Cas may evolve into a broken-contact configuration as predicted by TRO theory.
Evaluation of the Therapeutic Effect of a Flavonoid Prescription against Rabbit Hemorrhagic Disease In Vivo
Authors: Du Hongxu , Zhang Shuaibing , He Miao , Ming Ke , Wang Jinli , Yuan Wenjuan , Qiao Mingyu , Wu Yi , Wang Deyun , Hu Yuanliang , Liu Jiaguo
Published: April 2019

Rabbit hemorrhagic disease (RHD) is an acute, high fatal contagious disease induced by rabbit hemorrhagic disease virus (RHDV) with acute severe hepatic injury and causes huge economic loss worldwide. In order to develop an effective and reliable drug to treat this disease in clinic, a prescription formulated with baicalin, linarin, icariin, and notoginsenoside R1 (BLIN) according to the theory of syndrome differentiation and treatment in traditional Chinese veterinary medicine was applied to investigate its curative effects against RHD in vivo. The preliminary study results showed that BLIN prescription exerted good curative effect on RHD therapy. To further validate the curative effect and to investigate the possible related curative mechanisms of this drug, the survival rates, the plasma biochemical indexes of hepatic function, the plasma evaluation indexes of oxidative injury, and the RHDV gene expression levels were detected and then the correlation among these indexes was also analyzed. These results showed that BLIN prescription could significantly increase the survival rate, reduce the hepatic injury severity, alleviate the oxidative injury, and decrease the RHDV gene expression level in rabbits infected with RHDV. All these results indicate that BLIN prescription possesses outstanding curative effect against RHD, and the curative mechanism may be related to its antioxidant and anti-RHDV activities. Therefore, this prescription can be expected to be exploited into a new candidate for RHD therapy in clinic.
Transient Periictal Brain Imaging Abnormality in a Saudi Patient with Probable Celiac Disease Epilepsy and Occipital Calcification Syndrome
Authors: Khan Soha , AlNajjar Asma , Alquaydheb Abdullah , Nahrir Shahpar
Published: April 2019

Celiac disease epilepsy and occipital calcification (CEC) syndrome is a rare, emerging disease first described in 1992. To date, fewer than 200 cases have been reported worldwide. CEC syndrome is generally thought to be a genetic, noninherited, and ethnically and geographically restricted disease in Mediterranean countries. However, we report the first ever case of probable CEC in a Saudi patient. Furthermore, the patient manifested a magnitude of brain magnetic resonance imaging (MRI) signal abnormalities during the periictal period which, to the best of our knowledge, has never been described in CEC. The brain MRI revealed diffusion-weighted imaging (DWI) restriction with a concordant area of apparent diffusion coefficient (ADC) hypointensity around bilateral occipital area of calcification. An imbalance between the heightened energy demand during ictal phase of the seizure and unadjusted blood supply may have caused an electric pump failure and cytotoxic edema, which then led to DWI/ADC signal alteration.
Separation of Levofloxacin from Industry Effluents Using Novel Magnetic Nanocomposite and Membranes Hybrid Processes
Authors: Ullah Azmat , Zahoor Muhammad , Alam Sultan , Ullah Riaz , Alqahtani Ali S. , Mahmood Hafiz Majid
Published: April 2019

Magnetic carbon nanocomposite (MCN) was synthesized from waste biomass precursor, pineapple. The prepared adsorbent was characterized using different instrumental techniques and was used to remove levofloxacin (LEV) from effluents. The maximum sorption of LEV was observed at pH 7. Pseudo-2nd-order (PSO) kinetic was found to be the best model that fits well the adsorption kinetics data. For Langmuir adsorption isotherm, the R2 value was higher as compared with other isotherms. The Van’t Hoff equation was used for thermodynamic parameters determinations. ΔS° (standard entropy) was positive and ΔG° (standard Gibb’s free energy) was negative: -0.37, -1.81, and -3.73 kJmol−1 corresponding to 25, 40, and 60°C. The negative values of ΔG° at different temperatures stipulate that the adsorption of LEV was spontaneous in nature and adsorbent has a considerable affinity for LEV molecules. The MCN was then utilized in hybrid way by connecting with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes in series and as a result enhanced permeate fluxes were observed. The percent retention of LEV molecules was lower with UF membrane and with NF it was 96%, while it was 100% with RO. For MCN/UF and MCN/NF systems, improvement in % retention was recorded.
Experimental Scedosporiosis Induces Cerebral Oedema Associated with Abscess regarding Aquaporin-4 and Nrf-2 Depletions
Authors: Ampawong Sumate , Luplertlop Natthanej
Published: April 2019

Cerebral involvement especially brain abscess is life-threatening complication and major cause of death during Scedosporium apiospermum infection. However, little is known about pathogenesis of brain oedema associated with abscess in scedosporiosis. Experimental scedosporiosis was conducted in BALB/cMlac mice to characterize the presence of brain oedema, its type, and its related mechanisms focusing on aquaporin (AQP)-4, nuclear factor erythroid-2 related factor (Nrf-2), and tumor necrotic factor (TNF)-α. The results revealed that S. apiospermum infection induced severe inflammatory environment relevant to TNF-α expression and cytogenic oedema-associated brain abscess predominately in cerebrum of immunocompromised mice without voriconazole treatment reflecting to downregulation of AQP-4 in neighboring abscess areas and oedematous blood vessels. Downregulation of Nrf-2 in neuronal cells and myelin degeneration were significantly observed in nontreated mice. In summary, oxidative stress, severe inflammatory response, and space-occupying mass from abscess formation inducing tissue hypoxia might be the postulate causes of oedema induced by scedosporiosis.
Classification and Morphological Parameters of the Calcaneal Talar Facet: Which Type Is More Likely to Cause Osteoarthritis in Chinese Population?
Authors: Yang Yi , Cheng Han-wen , Xiong Zheng-rong , Liu Nian , Liu Yang , Wang Yi , Zeng Yan , Fu Shi-jie , Zhang Lei
Published: April 2019

Due to the calcaneal osteoarthritis, patients had a lower quality of life. This research was to study which type of calcaneus was more likely to cause osteoarthritis and then to guide the clinical prevention and treatment in Chinese population. All 505 intact Chinese calcaneus facets were reconstructed by CT-3D reconstruction scanner and classified into five types based on the calcaneal talar facet (CTF) configuration. CTF’s morphology parameters (osteophyte, cortical thickness of calcaneus, GIssane’s and Bohler’s angle, and long and short axis) were measured and recorded by PACS CT system. Researchers used the length of long and short axis to calculate the CTF area. By comparing the morphology parameters of five types of calcaneus, the differences among different types of calcaneus in Chinese people were statistically different. The study showed that Type II and Type IV had the highest percentage of osteophytes. After being compared and analyzed, the CTF pressure and the subtalar joint stability were closely related to the occurrence of osteoarthritis. Based on the measurement and comparison of morphological parameters in this study, Types II and IV were the most likely to develop osteoarthritis in Chinese population.
SUBBASE: An Authentication Scheme for Wireless Sensor Networks Based on User Biometrics
Authors: Riaz Rabia , Gillani Noor-ul-Ain , Rizvi SanamShahla , Shokat Sana , Kwon Se Jin
Published: April 2019

To keep a network secure, a user authentication scheme that allows only authenticated users to access network services is required. However, the limited resources of sensor nodes make providing authentication a challenging task. We therefore propose a new method of security for a wireless sensor network (WSN). Our technique, Secure User Biometric Based Authentication Scheme (SUBBASe), is based on the user biometrics for WSNs. It achieves a higher security level as well as improved network performance. This solution consists of easy operations and light computations. Herein, the proposed technique is evaluated and compared with previous existing techniques. This scheme increases the performance of the network by reducing network traffic, defending against DOS attacks, and increasing the battery life of a node. Consequently, the functionality and performance of the entire network is improved.
Multilayer Shielding Design for Intermediate Radioactive Waste Storage Drums: A Comparative Study between FLUKA and QAD-CGA
Authors: Li Wenqian , Liu Xuegang , Li Ming , Huang Yilin , Fang Sheng
Published: April 2019

To ensure that the outside dose rate of waste package is below the limitation of national laws and regulations, based on the standard 200L drum, a new drum with inner shielding was proposed for intermediate-level radioactive waste (ILW) storage. For comparison, FLUKA and QAD-CGA were used to verify the shielding design of the ILW storage drums produced in INET with multiple inner shielding layers. The flux and dose were calculated and analyzed for four different cases. In QAD-CGA calculation, it was found that different buildup factors can lead to the considerably different results. A weighted algorithm was proposed to correct QAD-CGA for multilayer shielding cases. In FLUKA calculation, parameter optimization and tailored variance reduction technique (VRT) were used. Quantitative efficiency evaluation of different FLUKA settings using the FOM factor was carried out. The differences in the calculated dose rates results between the FLUKA and QAD-CGA programs are within one order of magnitude. The results of QAD-CGA are generally higher than those of FLUKA. The analysis shows that appropriate corrections in QAD-CGA can make the trend of the calculation results more consistent with the theory. In FLUKA calculation, with optimized setting and VRT adopted, the calculation efficiency can be improved more than 20 times. The results of this study provide not only suggestions for the design of the ILW storage drums but also useful references for other similar work.
Inferred Industrial and Agricultural Activities Impact on Groundwater Quality of Skhira Coastal Phreatic Aquifer in Southeast of Tunisia (Mediterranean Region)
Authors: Melki Samira , El Asmi Amina Mabrouk , Gueddari Moncef
Published: April 2019

In Tunisia, it has been proven through various previously published studies that agricultural overexploitation and urban and industrial activities increase the risk of groundwater quality deterioration. The present study is a new research to be added to groundwater appraisal and comes to assess groundwater quality of the phreatic Skhira aquifer in relation to surrounding anthropic activities and also tries to evaluate potential risk threatenings of the local population. For that, 20 water well samples covering the phreatic aquifer were analyzed for physical and chemical parameters, major cations and anions, nutrient elements, fluorine, and some trace metal elements. Results show that the area close to the phosphogypsum storage site is the zone which is the most affected by industrial activity. This area corresponds to the upstream part of the aquifer, in terms of the trending flow, and records the highest conductivity values, high H2PO4-, F-, SO42-, and Zn2+ concentrations. Groundwater samples in this area are also characterized by a relatively low hydrogen potential (acid pH). High NO3- are recorded especially upstream of the aquifer and are thought to be caused by high fertilizer use. Overall, most analyzed samples do not meet the World Health Organization norms and therefore are not suitable as drinking waters. In addition, well water use for irrigation represents a medium to high sodicity and alkanization risk. The current study sheds light on the increasing deterioration risk of the aquifer and is an awakening call for decision-makers to imply means for urgent solutions.
Cryopreservation of Shoot Tips of Elite Cultivars of Cannabis sativa L. by Droplet Vitrification
Authors: Uchendu Esther , Lata Hemant , Chandra Suman , Khan Ikhlas A. , ElSohly Mahmoud A.
Published: April 2019

Cannabis sativa L. (marijuana or hemp) is recognized worldwide for its psychoactive properties as well as for fiber production. This study focused on the evaluation of 3 droplet vitrification protocols for long-term conservation of shoot tips in liquid nitrogen (LN). Shoot tips (∼0.5 mm) were excised from 3- to 4-week-old in vitro-grown shoots of 3 cultivars (MX, VI-20, and B-5: high tetrahydrocannabinol [THC], high cannabidiol [CBD], and intermediate THC∼CBD, respectively) and pretreated on 5% dimethyl sulfoxide agar plates for 48 h. The shoot tips were then vitrified in LN using 3 separate cryoprotectant (plant vitrification solutions [PVS] #2, #3, and #4) droplets on an aluminum cryoplate. There was no significant difference between the regrowth of cryopreserved shoot tips exposed to PVS2 for 15 and 20 min, but regrowth of all 3 cultivars significantly declined after 20 min of exposure. Exposure duration of 15 min was adapted for subsequent experiments. Regrowth of cryopreserved MX was significantly higher with PVS2 (63%) than with PVS3 and PVS4 (≤5%). Regrowth of cryopreserved VI-20 was highest with PVS2 (57%) and significantly higher than with PVS3 and PVS4 (≤25%). The regrowth of cryopreserved shoot tips of B-5 was significantly different between all 3 protocols with PVS2 > PVS4 > PVS3. Both PVS2 and PVS4 produced regrowth above 55%, while regrowth with PVS3 was significantly lower (31%). These results indicate that 15–20 min of exposure to PVS2 are most suitable for cryopreservation of these varieties. This is the first report on protocol development for the cryopreservation of organized tissues of C. sativa L. for germplasm conservation.
РЕТРОСПЕКТИВНИЙ АНАЛІЗ ЗАХВОРЮВАНОСТІ НА НЕГОСПІТАЛЬНУ ПНЕВМОНІЮ СЕРЕД ВІЛ-ПОЗИТИВНИХ ОСІБ У ХАРКОВІ ЗА ПЕРІОД 2013-2017 рр.
Authors: Tsyko O. V. , Kozko V. M. , Yurchenko I. S.
Published: April 2019

Мета роботи – провести ретроспективний та структурний аналіз інфекційної захворюваності на легеневу патологію серед ВІЛ-інфікованих осіб, які перебували на лікуванні в ОКІЛ м. Харкова за період 2013-2017 рр. Окремо виділити кількість випадків бактерійної пневмонії на тлі ВІЛ упродовж зазначеного періоду, визначити фактори ризику її виникнення, клінічні особливості перебігу, діагностику залежно від імунного статусу, особливості лікування та можливості профілактики.

Матеріали і методи. Проведений ретроспективний аналіз захворюваності ВІЛ-інфікованих осіб на патологію легень з використанням 191 медичної картки стаціонарного хворого, з яких відібрано 102 історії хвороби ВІЛ-інфікованих з бактерійною пневмонією, які перебували на лікуванні у стаціонарі ОКІЛ за період 2013-2017 рр. Статистичну обробку отриманих даних здійснювали методами варіаційної та кореляційної статистики із застосуванням програмного забезпечення.

Результати досліджень та їх обговорення. Негоспітальна бактерійна пневмонія у ВІЛ-позитивних осіб виникає при будь-якому рівні CD4+ T-лімфоцитів в 1 мкл, частота її прогресивно збільшується у міру поглиблення імунодепресії. Клінічний перебіг не відрізняється від осіб з ВІЛ-негативним статусом, але при зниженні CD4+ T-лімфоцитів <50 в 1 мкл має тяжчий перебіг та ознаки інвазивності традиційного збудника, особливо в асоціації з Candida albicans та/або Pneumocystis jiroveci.

Висновки. За досліджуваний період з 2013 по 2017 рр. кількість випадків негоспітальної бактерійної пневмонії на тлі ВІЛ збільшилась. Факторами, що підвищують ризик її виникнення є вживання наркотичних речовин, зловживання алкоголем і куріння, а також низьке охоплення АРТ. Збудник з мокроти був виділений в 26,5 % випадків. Більш тяжкий перебіг бактерійної пневмонії був у групі хворих з кількістю CD4+ T-лімфоцитів <50 в 1 мкл, бактеріологічно в мокротинні таких хворих крім банального збудника була Candida albicans та/або Pneumocystis jiroveci, що ускладнювало клінічну картину. Рентгенологічно при цьому була тенденція до генералізації процесу в легенях. Мультипрофілактики виникнення негоспітальної бактерійної пневмонії у ВІЛ-інфікованих через величезну кількість її збудників немає, тому ризик її виникнення у цієї категорії буде завжди вищим, ніж в цілому в популяції. Єдиними рекомендаціями щодо профілактики є використання 23-валентної полісахаридної пневмококової вакцини та щорічна вакцинація від грипу.
ЕТІОЛОГІЧНА СТРУКТУРА ГОСТРОГО ЛАЙМ-БОРЕЛІОЗУ ЗА ВИДАМИ ЗБУДНИКА
Authors: Shkilna M. I.
Published: April 2019

Мета дослідження – встановити частоту інфікування різними видами борелій пацієнтів із гострою формою Лайм-бореліозу (мігруючою еритемою та Лайм-артритом) в Тернопільській області.

Пацієнти і методи. Під спостереженням було 48 пацієнтів з гострою формою хвороби Лайма у віці від 19 до 65 років, які в 2018 р. перебували на амбулаторному та стаціонарному лікуванні в Тернопільському обласному клінічному шкірно-венерологічному диспансері та Університетській лікарні; серед них 19 (39,6 %) чоловіків і 29 (60,4 %) жінок. Пацієнтів поділили на дві групи: 34 (I група) – хворі на мігруючу еритему (МЕ) та 14 (II група) – на Лайм-артрит (ЛА). Діагноз Лайм-бореліозу підтверджували анамнестично, клінічно та серологічно. Специфічний діагноз встановлювали за наявності в сироватці крові пацієнтів специфічних IgМ і (або) IgG до комплексу B. burgdorferi sencu lato (s. l.) методом ELISA та лише IgМ, за допомогою реакції імунного блотингу (EUROLINE Borrelia RN-AT adv.).

Результати. Позитивні або проміжні результати серологічного дослідження сироваток крові на наявність специфічних IgM і IgG до комплексу B. burgdorferi s. l. (B. burgdorferi sensu stricto (s. s.), B. garinii, B. afzelii) за допомогою тесту ELISA (хоча б одного класу антитіл) знайдено в 24 (70,6 %) із 34 пацієнтів з мігруючою еритемою та 11 (78,6 %) з Лайм-артритом. Порівняння частоти діагностики специфічних антитіл IgM (позитивних і проміжних) до B. burgdorferi s. l. (B. burgdorferi s. s., B. garinii, B. afzelii та B. spielmanii) у 34 пацієнтів з мігруючою еритемою, методом ІФА – та імуноблоту, показало, що вона була вища при використанні імуноблоту: 76,5 % порівняно із методом ІФА 55,9 % (р<0,05). Вивчення етіологічної структури гострого Лайм-бореліозу в 26 пацієнтів з мігруючою еритемою (I група) та 12 – із Лайм-артритом (II група) встановило, що OspC B. spielmanii знайдено у 24 (92,3 %) пацієнтів I групи та 12 (100 %) пацієнтів з II.

Висновки. Специфічні IgG у тесті ELISA було виявлено лише в сироватці крові 35,3 % пацієнтів з мігруючою еритемою, що може свідчити про імунну пам’ять або хронічний процес. Гуморальну відповідь на поверхневий антиген (OspC) B. spielmanii встановлено в 92,3 % пацієнтів з мігруючими еритемами та всіх хворих із гострим Лайм-артритом.
Impact of Hemodynamic Ramp Test-Guided HVAD Speed and Medication Adjustments on Clinical Outcomes
Authors: Uriel Nir , Burkhoff Daniel , Rich Jonathan D. , Drakos Stavros G. , Teuteberg Jeffrey J. , Imamura Teruhiko , Rodgers Daniel , Raikhelkar Jayant , Vorovich Esther E. , Selzman Craig H. , Kim Gene , Sayer Gabriel
Published: April 2019

Background:

Hemodynamic ramp (HR) tests can guide the optimization of left ventricular assist device (LVAD) speed and direct medical therapy. We investigated the effects of HR-guided LVAD management.

Methods and Results:

This prospective, multicenter, randomized, pilot study compared outcomes in LVAD patients using an HR-guided (HR group) versus a standard transthoracic echocardiography-guided (control group) management strategy. Patients were enrolled and randomized 1 to 3 months post-HVAD implantation and followed for 6 months. Twenty-two patients (57±10 years, 73% male) were randomized to the HR group and 19 patients (51±13 years, 63% male) to the control group. HR group patients had double the number of LVAD speed changes (1.68 versus 0.84 changes/patient,
P
=0.09 with an incidence rate ratio 2.0, 95% CI, 0.9–4.7) with twice the magnitude of rotations per minute changes (130 versus 60 rotations per minute/patient,
P
=0.004) during the study. The HR group also had 2-fold greater heart failure medication changes (4.32 versus 2.53 changes/patient,
P
=0.072, incidence rate ratio 1.7 with 95% CI, 0.8–3.5) predominantly because of changes in diuretic dose (40 versus 0 mg/patient,
P
<0.001). The HR group had numerically but not statistically higher event-free survival (62% versus 46%,
P
=0.087; hazard ratio, 0.46 with 95% CI, 0.2–1.2), with numerically but not statistically lower events per patient-year (
P
=0.084). There were no significant differences in the 6-minute walk or Kansas City Cardiomyopathy Questionnaire tests at 6 months.

Conclusions:

In this randomized pilot study of LVAD patient management we demonstrated the feasibility of standardized HR testing at multiple institutions and that a strategy guided by hemodynamics was associated with more LVAD speed and medication adjustments and a nonsignificant reduction in adverse events. A pivotal study to demonstrate the clinical benefit of HR testing is warranted.

Clinical Trial Registration:

URL:
https://www.clinicaltrials.gov
. Unique identifier: NCT03021239.
Abstract 102: The Association of Patient Navigator Program Features and Hospital Strategies with Processes and Outcome Metrics in Acute Myocardial Infarction and Heart Failure
Authors: Albert Nancy M , Gluckman Ty J , McNamara Robert , Fonarow Gregg C , Malik Adnan , Brindis Ralph G , Lu Di , Negi Smita , Rogers Susan , Mobayed Julie
Published: April 2019

Background:
Association between hospital site-led structure, system and process changes, number of site-initiated technologies, the perceived value of program-directed services aimed at promoting quality improvement and process and outcome metrics achieved are unknown after a 2-year acute myocardial infarction and heart failure (AMI-HF) quality program.

Methods:
After participation in the Patient Navigator Program, hospitals (n=35) completed surveys on the implementation of structure, system and process changes, number of site-initiated technologies, and the perceived value of program directed educational calls and webinars, quality-focused site visits, use of a list-serv that facilitated site coordinator communication and data reports. Univariate analyses assessed the associations of each factor with 30-day unadjusted AMI-HF rehospitalization and in-hospital risk adjusted AMI death and 14 AMI-HF process metrics.

Results:
When hospital structure, system and process changes were high, sites were more likely to improve 30-day HF re-hospitalization,
p
=0.014. The number of site-initiated technologies and the value of using a list-serv to communicate with other program sites were not associated with outcome or process metric changes from baseline to 2 years. Sites that rated program-led educational calls and webinars as a high value were more likely to improve AMI-HF self-care education documentation,
p
=0.049. Sites that rated quality-related site visits as high value were more likely to improve left ventricular systolic dysfunction evaluation,
p
=0.035 and 30-day unadjusted AMI-HF rehospitalization rates (
p
=0.021 and 0.007, respectively). Sites who rated the value of data reports more highly were less likely to improve 30-day unadjusted AMI rehospitalization,
p
=0.006 and more likely to improve 30-day HF rehospitalization,
p
=0.033.

Conclusion:
Hospital-initiated structure-system-process changes and Patient Navigator Program-directed services that were perceived as high value, especially site visits and data reports, were more likely to be associated with improved 30-day HF re-hospitalization rates and some process improvements compared to baseline.
Abstract 108: Identifying and Addressing Gaps in Utilization of Cardiac Resynchronization Therapy
Authors: Bradley Steven M , Thomas Chelsey , Witt Shaina , Rush Pam , Strauss Craig E , Eckman Peter
Published: April 2019

Objective:
Prior registry studies have reported potential underutilization of cardiac resynchronization therapy (CRT) in clinical practice. We sought to identify and address gaps in the use of CRT among eligible patients in a large healthcare system.

Methods:
From the Allina Health enterprise data warehouse, we identified potentially eligible patients for CRT and refined eligibility assessment through detailed chart review. Following this eligibility assessment, patient lists were provided to cardiology providers who had last seen the patient in clinical care delivery to further review and refer for CRT as appropriate.

Results:
We identified 13,897 patients with a left ventricular ejection fraction of ≤ 35% by echocardiography performed between January 1, 2013 and November 13, 2018 (see Figure). We excluded 5,943 (42.8%) patients with QRS duration <120 ms on the first available ECG within one year of the index echocardiogram and 3,160 (22.7%) patients with no ECG during that time interval. We also excluded 917 (6.6%) patients with recovery of systolic function to >35% on a repeat echocardiogram performed ≥ 3 months after the index assessment and 1,772 (12.8%) patients without a follow-up echocardiogram at ≥ 3 months. Of the remaining 2,105 patients, 671 (31.9%) patients died in follow-up, 742 patients (35.2%) subsequently underwent CRT-D, 141 (6.7%) underwent CRT-P, 108 (5.1%) had further improvement in EF to >35% on the most recent echocardiogram, 46 (2.2%) had a most recent QRS duration <120 ms, and 20 (1.0%) underwent left ventricular assist device implantation or transplant, resulting in 377 (17.9%) patients potentially eligible for CRT. Following detailed chart review of 183 patients identified in this process, 73 (39.9%) patients remained eligible for CRT. These 73 patients were attributed to 41 different cardiology providers who further reviewed their clinical situation and referred 17 (9.3%) of these patients for CRT.

Conclusion:
Filtering a data repository on elements that determine CRT eligibility facilitated targeted chart review to address potential quality gaps in the use of this therapy. Only 9% of potentially eligible patients identified prior to chart review were ultimately referred for CRT, suggesting gaps in use of CRT may be smaller than suggested from prior registry studies.
Abstract 109: Impact of Socio-Economic Factors on Health Care Visits Among Patients with Heart Failure
Authors: Buhari Olajide , Atanda Adebayo , Atanda Oluwafunmilayo , Medhane Fitsumberhan , Alzharani Talal , Weerakoon Shaneke , Mercader Marco , Shirazi Mohammed , Temesgen Nardos , Faillace Robert , Borden William , Panjrath Gurusher
Published: April 2019

Background:
Ambulatory health care visits (HCVs) have substantial impact on heart failure (HF) outcomes. We tested the hypothesis that the number of HCVs vary by race, insurance status and other socioeconomic status (SES) factors among both hospitalized and non-hospitalized HF patients.

Methods:
Using the United States NHANES 2005-2016 database, 1154 individuals with HF were identified based on reported diagnosis. Multivariate logistic regression using the proportional odds model was performed with number of HCVs in 12 months as the dependent variable. Age, race, sex, educational status, income and insurance status were the independent variables. Survey procedures that account for the weighted, clustered sampling design, and non-response were used in the analysis.

Results:
Mean age of the sample was 67 years; including 51% females. Non-Hispanic whites, non-Hispanic blacks, and Hispanics accounted for 70 %, 16%, and 5% of the population, respectively. Multivariate analysis revealed that patients with insurance had a 2.5 greater odds of having more HCV compared to uninsured patients (OR 2.49,1.34-4.63 P=0.0042). There were no differences in women compared to men(OR 1.13, 0.84-1.51 P=0.42), Non-Hispanic whites compared to Hispanics (OR 1.183, 0.701-1.996 P=0.26), or people without a high school degree compared to those with a degree,(OR 1.343, 0.873-2.067 P=0.2815).

Conclusions:
Current analysis suggests an association between insurance status and number of HCVs. Unlike previous reports that considered hospitalized patients alone, the current analysis does not reveal significant racial or gender disparities.
Abstract 114: Trends in Aortic Valve Interventions in The Netherlands
Authors: Daeter Edgar J , van Veghel Dennis , Houterman Saskia , Olsthoorn Jules , Soliman-Hamad Mohamed A
Published: April 2019

Introduction:
Aortic valve disease is the leading valvular pathology in the Western World. Transcatheter aortic valve implantation (TAVI) have emerged as alternatives to surgical aortic valve replacement (SAVR). The study’s objective is to describe clinical trends in TAVI and SAVR in patients with aorta valve disease.

Method:
Within the Netherlands Heart Registry (NHR) trends were analyzed in isolated TAVI and SAVR among 14 centers in the Netherlands.

Results:
Between 2013 and 2017, a total of 7432 isolated SAVR and 5929 TAVI procedures have

been performed. An 43.9% (from 2174 to 3128) increase in the total number of SAVRs and TAVIs was observed, merely in het due to a 161% (from 669 to 1748) growth of TAVIs. In 2017, there was a slight decline in SVAR. In TAVI patients the 30-day and 120-day mortality decreased significantly, from 7.2% (40 of 558) and 10.6% (59 of 558) in 2013 to 3.4% (52 of 1540) and 5.7% (86 of 1509) in 2017 respectively. The risk adjusted outcomes showed a significant decrease in vascular complications in TAVI. The risk profile of TAVI patients has changed over time, with a trend towards decrease of risk: lower EuroSCORE and higher left ventricular ejection fraction.

Conclusion:
This registry showed a rapid increase in the use of TAVI for the treatment of aortic valve disease in the Netherlands. Importantly, early mortality rates declined as did the rate of complications. Furthermore, a trend towards decrease of risk was observed.