bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave‐assisted Synthesis and Bioevaluation of Some Semicarbazones
Authors: Jafri Laila , Ansari Farzana L. , Jamil Maryam , Kalsoom Saima , Qureishi Sana , Mirza Bushra
Published: February 2012

In continuation to our efforts in finding potential therapeutic agents, a variety of biologically significant semicarbazones were synthesized by the reaction of different carbonyl compounds with phenyl semicarbazides through microwave irradiation. Initially, 18 semicarbazones were studied for their antimicrobial, antitumor, and antioxidant potential. None of the tested compounds showed any antibacterial activity; however, some compounds showed significant antifungal activity. Interestingly, all compounds showed antitumor activity when tested against tumors grown on potato discs. These compounds were also tested for their effect on OH radical‐induced oxidative DNA damage. All the compounds showed DNA protection to varying extent. Based on the promising results of antitumor and antioxidant activities, another set of 24 semicarbazones was synthesized, and all of these semicarbazones were evaluated for their antioxidant potential. The results showed that the semicarbazones derived from 2‐nitrobenzaldehyde and acetophenone were the most active 2,2‐diphenyl‐1‐picrylhydrazyl 9 (DPPH) free radical scavengers. The overall results have led to the identification of some interesting compounds which seem to have great potential to be developed into effective anticancer drugs.
Comparison of a commercial ELISA with an indirect fluorescent antibody test to detect antibodies toLawsonia intracellularisin experimentally challenged pigs
Authors: Collins A , Gonsalves J , Fell S , Barchia I
Published: February 2012

Objective The ability of a new commercial ELISA to detect pigs with subclinical proliferative enteropathy (PE) was compared with the traditional indirect fluorescent antibody test (IFAT).

Methods Serum samples were selected from pigs with knownLawsonia intracellularisinfection status and clinical signs of PE, but the sample population consisted predominantly of pigs subclinically affected by PE.

Results Significant association and agreement were shown between the ELISA and IFAT assays. ELISA results correlated well with the duration ofL. intracellularisshedding as detected by polymerase chain reaction.

Conclusion ELISA can be successfully used to monitorL. intracellularisinfection in pigs.
Standing low‐field magnetic resonance imaging in horses with chronic foot pain
Authors: Gutierrez‐Nibeyro SD , Werpy NM , White II NA
Published: February 2012

Objective  Conventional imaging modalities can diagnose the source of foot pain in most cases, but have limitations in some horses, which can be overcome by using magnetic resonance imaging (MRI). However, there are no reports of the MRI appearance and prevalence of foot lesions of a large series of horses with chronic foot lameness.

Methods  In the present study, 79 horses with unilateral or bilateral forelimb lameness because of chronic foot pain underwent standing low‐field MRI to make a definitive diagnosis.

Results  Of the 79 horses, 74 (94%) had alterations in >1 structure in the lame or lamest foot. Navicular bone lesions occurred most frequently (78%) followed by navicular bursitis (57%), deep digital flexor tendonopathies (54%) and collateral desmopathy of the distal interphalangeal joint (39%). Effusion of the distal interphalangeal joint was also a frequent finding (53%).

Conclusion  Low‐field MRI in a standing patient can detect many lesions of the equine foot associated with chronic lameness without the need for general anaesthesia.
Identification of a periorbital wooden foreign body as the cause of chronic ocular discharge in a horse
Authors: Santos MP , Gutierrez‐Nibeyro SD , Stewart AA , Hyde RM , Rodgerson DH
Published: February 2012

The clinical, diagnostic and therapeutic features of a horse with a wooden foreign body embedded in the deep portion of the right masseter muscle adjacent to the right orbit are presented. The purpose of this report is to describe the clinical presentation, magnetic resonance imaging findings and treatment of a penetrating wooden foreign body in a horse that had no history of trauma or evidence of a puncture wound. This report documents the usefulness of magnetic resonance imaging to detect a wooden foreign body embedded in the soft tissues of a horse with a chronic copious ocular discharge. Two surgical procedures were necessary, which is a frequent complication encountered with wooden foreign bodies.
Toxicity and efficacy of a novel doxorubicin and carboplatin chemotherapy protocol for the treatment of canine appendicular osteosarcoma following limb amputation
Authors: Lane AE , Black ML , Wyatt KM
Published: February 2012

Objective To evaluate the safety and efficacy of a novel doxorubicin and carboplatin chemotherapy protocol for the treatment of dogs with appendicular osteosarcoma following limb amputation.

Design Retrospective study.

Procedure Dogs diagnosed with appendicular osteosarcoma, with no evidence of metastatic disease, treated with amputation and adjuvant chemotherapy consisting of two doses of doxorubicin given 14 days apart, followed by four doses of carboplatin at 3‐weekly intervals between September 2003 and December 2009 were identified from the medical records of Perth Veterinary Oncology. Haematological and gastrointestinal toxicities were assessed based on information in the medical records and recorded complete blood count results. The efficacy of the protocol was assessed by determining the median disease‐free interval (DFI) and overall survival time (OST) using the Kaplan‐Meier product‐limit method.

Results In total, 33 dogs met the inclusion criteria. The median DFI was 231.5 days and the median OST was 247 days. With regard to haematological toxicity, 56% of dogs had a grade 1–2 neutropenia recorded as their highest marrow toxicity and 9% of dogs experienced a grade 3–4 neutropenia, all subsequent to doxorubicin administration. The highest gastrointestinal toxicity was grade 1–2 in 15 dogs (47%) and 5 dogs (16%) experienced grade 3–4 gastrointestinal toxicity.

Conclusion This chemotherapy protocol did not result in a longer time to disease recurrence or OST in this population of dogs. Dual‐agent protocols have failed to improve survival times and therefore we conclude that a single‐agent protocol using carboplatin may be equally effective with less toxicity.
In this issue – March 2012
Authors: Jackson AE
Published: February 2012

Maximal movement initiation in Greyhounds · Novel chemotherapy protocol for osteosarcoma · Low‐field MRI for equine foot conditions · Periorbital wooden foreign body · Effect of plastic clips in sheep · Comparison of diagnostic tests for Lawsonia in pigs · Student vs employer expectations
The spectrum of T‐cell and natural killer/T‐cell neoplasms with leukaemic presentation in a single institution in Taiwan
Authors: CHANG S.‐T. , HSIEH Y.‐C. , KUO S.‐Y. , LU C.‐L. , CHU J.‐S. , CHUANG S.‐S.
Published: February 2012

T cell and natural killer (NK)/T‐cell neoplasms are rare and may occasionally present as leukaemia. We retrospectively searched T cell and NK/T‐cell tumours in a single institution in Taiwan from January 2000 to December 2009 and identified 137 (19.1%) patients with T cell and NK/T‐cell tumours among 718 patients with lymphoid neoplasms. Among these 137 patients, 18 (13.1%) presented with leukaemia including T‐lymphoblastic lymphoma/leukaemia (T‐LBL), T‐cell prolymphocytic leukaemia, aggressive NK‐cell leukaemia, adult T‐cell lymphoma/leukaemia (ATLL), T‐cell large granular lymphocytic (T‐LGL) leukaemia and unspecified peripheral T‐cell lymphoma. Cases with concurrent lymphoma, higher absolute leukaemic cell counts and elevated lactate dehydrogenase level carried a poorer prognosis. The survival was dichotomous, with a very poor prognosis for patients with T‐LBL, T‐cell prolymphocytic leukaemia, aggressive NK‐cell leukaemia, ATLL in acute phase and unspecified peripheral T‐cell lymphoma, while those with T‐LGL leukaemia and ATLL in chronic phase had a favourable outcome.
A reliable method for sexing unincubated bird eggs for studying primary sex ratio
Authors: ASLAM M. AAMIR , HULST MARCEL , HOVING‐BOLINK RITA A. H. , De WIT AGNES A. C. , SMITS MARI A. , WOELDERS HENRI
Published: February 2012

In birds, offspring sex ratio manipulation by mothers is now well established with potentially important consequences for evolution and animal breeding. In most studies on primary sex ratio of birds, eggs are sexed after incubation by the use of PCR methods targeted to the sex‐linkedCHD1genes. Sexing of unincubated eggs would be preferred, but as fertile and infertile blastodiscs cannot be distinguished macroscopically, errors could arise from PCR amplifications of parental DNA associated with the vitelline membrane of infertile eggs. In this study, we stained blastodiscs without the vitelline membrane with Hoechst 33342. This allowed unequivocal distinction between fertile and infertile blastodiscs. Fertile blastodiscs contained thousands of fluorescent nuclei, whereas no nuclei were seen in infertile eggs. In addition, after nucleic acid analysis, fertile blastodiscs yielded much stronger chromosomal DNA andCHD1‐targeted PCR bands on agarose gels compared with infertile blastodiscs. These findings indicate that fertile blastodiscs contain much more embryonic DNA than parental DNA, allowing reliable sexing of the fertile eggs. The differences between fertile and infertile blastodiscs in chromosomal DNA andCHD1PCR banding intensities alone could also be used to distinguish fertile from infertile eggs without using Hoechst staining. We conclude that identifying fertile blastodiscs either by Hoechst staining or by analyzing the yield of chromosomal DNA andCHD1‐PCR products, combined withCHD1‐targeted PCR amplification, presents an easy and reliable method to sex unincubated eggs.
QST in a hierarchically structured population
Authors: WHITLOCK MICHAEL C. , GILBERT KIMBERLY J.
Published: February 2012

Under some circumstances, selection and drift can be disentangled with comparisons of the QST of a quantitative trait and the FST of putatively neutral loci. Most previous comparisons of FST and QST are carried out at a single spatial scale. We derive a hierarchical QST appropriate for study across varying levels of spatial structure.
Does acupuncture relieve tinnitus?
Authors: Stener‐Victorin E
Published: February 2012

Wang K, Bugge J, Bugge S.

A randomised, placebo‐controlled trial of manual and electrical acupuncture for the treatment of tinnitus.

Complement Ther Med 2010; 18: 249–55.
Massage therapy to improve sleep quality post coronary artery bypass graft surgery
Authors: Lim CE Danforn , Cheng NCL
Published: February 2012

Nerbass FB, Feltrim MIZ, de Souza SA, Ykeda DS, Lorenzi‐Filho G.

Effects of massage therapy on sleep quality after coronary artery bypass graft surgery.

Clinics 2010; 65: 1105–10.
Clinical efficacy of a Phaseolus vulgaris and Cynara scolymus mixture on satiety
Authors: Chrubasik S
Published: February 2012

Rondanelli M, Giacosa A, Orsini F, Opizzi A, Villani S.

Appetite control and glycaemia reduction in overweight subjects treated with a combination of two highly standardized extracts from Phaseolus vulgaris and Cynara scolymus.

Phytother Res 2011; 25: 1275–82.
Acupressure wristbands for the prevention of nausea and vomiting during labour and delivery
Authors: Li D
Published: February 2012

Sinha A, Paech MJ, Thew ME, Rhodes M, Luscombe K, Nathan E.

A randomised, double‐blinded, placebo‐controlled study of acupressure wristbands for the prevention of nausea and vomiting during labour and delivery.

Int J Obstet Anesth 2011; 20: 110–17.
Assessment of Current Chemiluminescence Kinetics Models at Engine Conditions
Authors: Petersen Eric , Kopp Madeleine , Donato Nicole , Güthe Felix
Published: February 2012

Chemiluminescence continues to be of interest as a cost-effective optical diagnostic for gas turbine combustor health monitoring. However, most chemical kinetics mechanisms of the chemiluminescence of target species such as OH*, CH*, and CO2* were developed from atmospheric-pressure data. The present paper presents a study wherein the ability of current kinetics models to predict the chemiluminescence trends at engine pressures was assessed. Shock-tube experiments were performed in highly diluted mixtures of H2/O2/Ar at a wide range of pressures to evaluate the ability of a current kinetics model to predict the measured trends. At elevated pressures up to 15 atm, the currently used reaction rate of H + O + M = OH* + M (i.e., without any pressure dependence) significantly over predicts the amount of OH* formed. Other important chemiluminescence species include CH* and CO2*, and separate experiments were performed to assess the validity of existing chemical kinetics mechanisms for both of these species at elevated pressures. A pressure excursion using methane-oxygen mixtures highly diluted in argon was performed up to about 15 atm, and the time histories of CH* and CO2* were measured over a range of temperatures from about 1700 to 2300 K. It was found that the existing CH* mechanism captured the T and P trends rather well, but the CO2* mechanism did a poor job of capturing both the temperature and pressure behavior. With respect to the modeling of collider species, it was found that the current OH* model performs well for N2, but some improvements can be made for CO2.
Effect of Thickness of Pd Plating Layer on Shear Strength of Lead-Free Solder Ball Joint With Electroless Ni/Pd/Au Plated Electrode
Authors: Kano Takahiro , Shohji Ikuo , Tsuchida Tetsuyuki , Ookubo Toshikazu
Published: February 2012

An electroless Ni/Pd/Au plated electrode is expected to be used as an electrode material for lead-free solder to improve joint reliability. The aim of this study is to investigate the effect of the thickness of the Pd layer on joint properties of the lead-free solder joint with the electroless Ni/Pd/Au plated electrode. Solder ball joints were fabricated with Sn-3Ag-0.5Cu (mass%) lead-free solder balls and electroless Ni/Pd/Au and Ni/Au plated electrodes. Ball shear force and microstructure of the joint were investigated. The (Cu,Ni)6Sn5 reaction layer formed in the joint interface in all specimens. The thickness of the reaction layer decreased with increasing the thickness of the Pd layer. In the joint with a Pd layer 0.36 μm thick, the remained Pd layer was observed in the joint interface. In the joint, impact shear force decreased compared with that of the joint without the remained Pd layer. On the contrary, when the thickness of the Pd layer was less than 0.36 μm, the Pd layer was not remained in the joint interface and impact shear force improved. Impact shear force of the joint with the electroless Ni/Pd/Au plated electrode was higher than that with the electroless Ni/Au one.
Wicking and Thermal Characteristics of Micropillared Structures for Use in Passive Heat Spreaders
Authors: Ranjan Ram , Patel Abhijeet , Garimella Suresh V. , Murthy Jayathi Y.
Published: February 2012

The thermal and hydrodynamic performance of passive two-phase cooling devices such as heat pipes and vapor chambers is limited by the capabilities of the capillary wick structures employed. The desired characteristics of wick microstructures are high permeability, high wicking capability and large extended meniscus area that sustains thin-film evaporation. Choices of scale and porosity of wick structures lead to tradeoffs between the desired characteristics. In the present work, models are developed to predict the capillary pressure, permeability and thin-film evaporation rates of various micropillared geometries. Novel wicking geometries such as conical and pyramidal pillars on a surface are proposed which provide high permeability, good thermal contact with the substrate and large thin-film evaporation rates. A comparison between three different micropillared geometries — cylindrical, conical and pyramidal — is presented and compared to the performance of conventional sintered particle wicks. The present work demonstrates a basis for reverse-engineering wick microstructures that can provide superior performance in phase-change cooling devices.
Study of Interfacial Reaction and Electromigration Reliability of Pb-Free Solders With Nickel Iron Barrier Layer
Authors: Lu Minhua , Lauro Paul , Goldsmith Charles
Published: February 2012

A study of NiFe alloy as under bump metallurgy (UBM) for Pb-free interconnect has been performed. Intermetallic growth rate of NiFe and SnAg solder is about 10x slower than that of Ni and SnAg solder. The thin and uniform intermetallic compound FeSn2 showed excellent thermal and electromigration stability. By slowing down or stopping the UBM dissolution, NiFe effectively eliminated the early EM fails that are common with Ni UBM. NiFe is an interesting candidate for the chip and substrate surface metallurgy of Pb-free interconnects for high power applications.
Change of the Electronic Conductivity of Carbon Nanotube and Graphene Sheets Caused by a Three-Dimensional Strain Field
Authors: Ohnishi Masato , Suzuki Yusuke , Ohashi Yusuke , Suzuki Ken , Miura Hideo
Published: February 2012

In this study, the change of the resistivity of carbon nanotubes and graphene sheets under strain was analyzed by applying a quantum chemical molecular dynamics analysis and the first principle calculation. Various combinations of double-walled carbon nanotube structures were modeled for the analysis. The change of the band structure was calculated by changing the amplitude of the applied strain. It was found in some cases that the band structure changes drastically from metallic band structure to semiconductive one, and this result clearly indicated that the electronic conductivity of the MWCNT decreased significantly in a three-dimensional strain field. It was also found that there is a critical strain at which the electronic band structure changes from metallic to semiconductive and vice versa. This result indicated that the metallic CNT changes a semiconductive CNT depending on the applied strain field. The effect of the diameter of the zigzag type CNT on the critical strain of buckling deformation was analyzed under uni-axial strain. In this analysis, the aspect ratio of each structure was fixed at 10. It was found that the critical strain decreased monotonically with the decrease of the diameter. This was because that the flexural rigidity of a cylinder decreased with the decrease of its diameter when the thickness of the wall of the cylinder was fixed. It was found that the critical strain decreased drastically from about 5% to 0.5% when the aspect ratio was changed from 10 to 30. Since the typical aspect ratio of CNTs often exceeds 1000, most CNTs should show buckling deformation when an axial compressive strain is applied to the CNTs. Finally, the shape of a six-membered ring of the CNT was found to be the dominant factor that determines the electronic band structure of a CNT. The change of the band structure of a grapheme sheet was analyzed by applying the abinitio calculation based on density functional theory. It was found that the fluctuation of the atomic distance among the six-membered ring is the most dominant factor of the electronic band structure. When the fluctuation exceeded about 10%, band gap appeared in the deformed six-membered ring, and thus, the electronic conductivity of the grapheme sheet change from metallic one to semiconductive one. It is therefore, possible to predict the change of the electronic conductivity of a CNT by considering the local shape of a six-membered ring in the deformed CNT.
Real-Time Data Center Transient Analysis
Authors: Zhang Xuanhang Simon , VanGilder James W.
Published: February 2012

A software tool was developed to predict the transient cooling performance of data centers and to explore various alternatives in real-time for data center design and management purposes. Cooling performance can be affected by factors such as room architecture, rack population and layout, connections between cooler fans and UPSs, chilled water pumps and UPSs, the size of the chilled water storage tank, etc. The available transient cooling runtime is mainly dictated by the system stored cooling capacity and the total load in the data center. This paper discusses the transient response of data centers to different design and failure scenarios and details a comprehensive and efficient approach for simulating this performance.
Dependence of Flow Boiling Heat Transfer Coefficient on Location and Vapor Quality in a Microchannel Heat Sink
Authors: Patel Ravi S. , Harirchian Tannaz , Garimella Suresh V.
Published: February 2012

Experiments were conducted to determine the influence of local vapor quality on local heat transfer coefficient in flow boiling in an array of microchannels. Additionally, the variation of local heat transfer coefficient along the length and width of the microchannel heat sink for given operating conditions was investigated over a range of flow parameters. Each test piece includes a silicon parallel microchannel heat sink with 25 integrated heaters and 25 temperature sensors arranged in a 5×5 grid, allowing for uniform heat dissipation and local temperature measurements. Channel dimensions ranged from 100 μm to 400 μm in depth and 100 μm to 5850 μm in width; the working fluid for all cases was the perfluorinated dielectric liquid, FC-77. The heat transfer coefficient is found to increase with increasing vapor quality, reach a peak, and then decrease rapidly due to partial dryout on the channel walls. The vapor quality at which the peak is observed shows a strong dependence on mass flux, occurring at lower vapor qualities with increasing mass flux for fixed channel dimensions. Variations in local heat transfer coefficient across the test piece were examined both along the flow direction and in a direction transverse to it; observed trends included variations due to entrance region effects, two-phase transition, non-uniform flow distribution, and channel wall dryout.
Server Heat Load Based CRAC Fan Controller Paired With Rear Door Heat Exchanger
Authors: Sundaralingam Vikneshan , Kumar Pramod , Joshi Yogendra
Published: February 2012

This paper discusses the preliminary design of a controller for the cooling air conditioning units (CRAC) fan speed based on server loads. The CRAC is paired with a rear door heat exchanger. The main purpose in implementing this controller is the reduce energy consumption and to have finer control in the provision of cooling within a data center. Tools that will be essential for developing this controller are CRACs with variable frequency drives (VFD), BCMS power monitoring, data archiving software (PI from OSISOFT) and MATLAB. For this experiment, the zone of interest in the data center consists of 10 racks of IBM Blade Centers with a maximum electrical load of approximately 24 kW each and a total of 3360 nodes. Results are compared with the conventional cooling method to quantify energy savings and corresponding chiller coefficient of performance (COP).
Stress Mapping Below Flip-Chip Bumps With High Spatial Resolution Using Piezoresistive CMOS Sensors
Authors: Lemke Benjamin , Paul Oliver , Ganapathysubramanian Shankar , Nardi Patrick , Baskaran Rajashree
Published: February 2012

This paper presents a CMOS stress sensor chip including arrays of piezoresistive sensor elements with high spatial resolution sensitive to the in-plane stress components σxx – σyy and σxy, to the out-of-plane stress σxz and σyz, and to the normal stress sum σΣ = (σxx + σyy)/2 − σzz. For the first time, an application of novel vertical stress sensors is presented, measuring the mechanical stress distributions below electroless nickel (eNi) bumps subject to lateral shear forces and vertical compression. All measured stress values are linearly proportional to the applied forces. The vertical shear stress sensors resolve residual vertical shear stresses of up to 51 MPa in the shear experiments. An adjustable numerical model is established assuming two different Young’s moduli of silicon nitride (SiN) emulating the adhesion between the SiN and eNi. Qualitative agreement of the in-plane stress distributions between experiment and numerical simulation is found in the shear and compression experiments, while good correlation for σΣ is found only for temperature uncompensated stress values in the compression test. The modeling of the absolute values shows differences to the experimental data of about ±30%.
The Effect of Under-Floor Obstructions on Data Center Perforated Tile Airflow
Authors: VanGilder James W. , Sheffer Zachary R. , Zhang Xuanhang Simon , O’Kane Collyn T.
Published: February 2012

Typical data center architectures utilize a raised floor; cooling airflow is pumped into an under-floor plenum and exits through perforated floor tiles located in front of IT equipment racks. The under-floor space is also a convenient place to locate critical building infrastructure, such as chilled-water piping and power and network cabling. Unfortunately, the presence of such objects can disrupt the distribution of cooling airflow. While the effects of other design parameters, such as room layout, plenum depth, perforated tile type, and leakage paths, have been systematically studied — and corresponding best-practices outlined, there is no specific advice in the literature with regard to the effect of under-floor infrastructure on airflow distribution. This paper studies the effects of such obstructions primarily through CFD analyses of several layouts based on actual facilities. Additionally, corresponding scenarios are analyzed using a Potential Flow Model (PFM), which includes a recently-proposed obstruction-modeling technique. It is found that under-floor obstructions significantly affect airflow distribution only when they are located very near perforated tiles and cooling units and occupy a substantial fraction of the total plenum depth.
Optimization of Outside Air Cooling in Data Centers
Authors: Kumari Niru , Shih Rocky , McReynolds Alan , Sharma Ratnesh , Christian Tom , Bash Cullen
Published: February 2012

Airside economizers in data centers introducing outside air directly in cold aisles or at CRAC level have been considered recently to reduce overall energy to cool IT equipment. However, such designs limit the operational envelope of free cooling based on the required supply air temperature to the IT equipment. More studies are required to optimize airside economizer layouts to increase the operation time and hence, increase the energy savings. This paper presents a case study of different outside air delivery configurations including outside air introduced in cold aisles, in plenum close to CRAC units’ supply side, at return side of CRAC units and in hot aisles. The temperature and flow fields are studied numerically and are compared to each other. Mixing of the cooler outside air with the hot air is studied to determine optimal local distribution of the outside air in a non-homogeneous data center to maximize natural cooling. The paper also quantifies the annual average performance of the outside air infrastructure to include the effects of the seasonal variations in the ambient temperature.
Effect of Oxygen Concentration on Damage Mechanism of Carbon Nanotubes Under High Current Density
Authors: Sasagawa Kazuhiko , Unuma Jun , Abo Takehiro
Published: February 2012

Multi-walled Carbon nanotube (MWCNT) has a great tolerance to electromigration (EM). Therefore, MWCNT is expected to be applied to via-material of electronic devices. But, the damage mechanism of MWCNT has not yet been revealed though oxidation by Joule heating and the EM by high density electron flow are proposed as causes of the MWCNT damage under high current density. In this study, we performed acceleration tests of MWCNT to reveal the damage mechanism of MWCNT under high current density. As a result of the acceleration test, lifetime in low vacuum condition with a low oxygen concentration was longer than that in the air. And, local evaporation of carbon due to oxidation appeared near the cathode end of CNT under both conditions. We confirmed presence of two mechanisms of CNT damage; oxidation and EM. It was shown that the oxidation mechanism at the damage site due to EM was enhanced under oxygen rich condition.
Fluidic Laser Beam Shaper by Using Thermal Lens Effect
Authors: Doan Hong Duc , Akamine Yoshihiko , Fushinobu Kazuyoshi
Published: February 2012

Laser measurement and laser processing techniques have been gaining strong attention from various applications [1,2]. This research aims at the development of a fluidic laser beam shaper, and in order to fulfill the objective, characteristics of the thermal lens effect are studied. This phenomenon has the optical property of a concave lens since the refractive index distribution on the optical axis is formed when the liquid is irradiated. One reason for the refractive index distribution in the liquid is the temperature distribution in the liquid when it is irradiated. In this research, effects of the pump power and propagation distance of the probe beam to probe beam profile are investigated experimentally and theoretically, in order to develop fluidic laser beam shaper. It is indicated that, by controlling some parameters in thermal lens system as pump power (in the regime of linear optics) and absorption coefficient, input Gaussian beam can be converted into flat-top beam profile. The relationship among the distance to obtain a flat-top beam, pump power and absorption coefficient is investigated to show the flexibility of fluidic laser beam shaper in many fields of laser application.
Effect of Compressive Loading on the Interconnect Reliability Under Thermal Cycling
Authors: Yu Da , Nguyen Tung , Lee Ho H. , Goo Namseo , Park S. B.
Published: February 2012

The ever increasing power density in modern semiconductor devices requires heat dissipation solution such as heat sink to remove the heat away from the device. A compressive loading was applied to reduce the interfacial thermal resistance between package and heat sink. In this study both numerical modeling and experimental approaches were employed to study the effect of compressive loading on the interconnect reliability, especially for high power density package, under thermal cycling loading conditions. The JEDEC standard thermal cycle tests were conducted and the resistance of the daisy chained circuits was in-situ measured to record the failure time. The failure analysis has been performed to indentify the failure modes of solder joint with and without the presence of compressive loading. A finite element based thermal fatigue life prediction model for SAC305 solder joint under compressive loading was also developed and validated with the experimental results.
Lead Free Flip Chip Reliability for Various Package Types
Authors: Islam Nokibul , Jimarez Miguel , Syed Ahmer , Hwang TaeKyeong , Gim JaeYun , Kang WonJoon
Published: February 2012

Flip Chip (FC) technology has now become the mainstream solution for high performance packages. From commercial gaming machines to high reliability servers, the FC package is gaining more market share over traditional packaging technologies, such as wire bond. Extensive research has been carried out to make the flip chip more robust, smaller foot prints, and excellent performance. FC packages are fabricated typically in two main configurations. Bare die FC packages leave the non active side of the die exposed. This allows the customer to apply their preferred heat dissipation scheme during board level attach. Lidded FC packages use a metallic lid attached to the die. Bare die package can be further subdivided into bare die underfilled package and bare die flip chip molded ball grid array (FCmBGA) package. Each of these packaging configurations has advantages as well as disadvantages. FCmBGA uses molding compound or EMC instead of capillary underfill, to protect FC die, and eliminate the need for a lid. Package warpage reduced a lot by adding a lid with the bare die FC package. However, the package and board level reliability for the above package types are still debatable. In this study test vehicles with three package types with bumps and BGAs are daisy chain to measure in situ data during accelerated tests. Impact of standard vs. low CTE (coefficient of thermal expansion) core substrate, accelerated temperature cycle conditions (temperature cycle condition “B”, “H”, and “J” according to JEDEC), and package level vs. package mounted on the board level reliability will be investigated. Comprehensive reliability data will help to select the right package type for next generation large die large body flip chip application.
Signal Integrity Analysis for RF System-in-Package
Authors: Chen Jeff , Li Weiping , Ling Feng
Published: February 2012

RF System-in-Package (SiP) has become a viable packaging platform, which offers great flexibility to integrate ICs with different processes and different architects. With operating frequency becoming higher and multiple available technologies embedded in one package, the system could fail due to the undesired noise coupling resulted from the close proximity of the components. Therefore, the design methodology with signal integrity (SI), power integrity (PI), and electromagnetic compatibility (EMC) analysis becomes essential to tackle the SiP integration issues. The paper presents a RF SiP design methodology with SI/PI/EMC simulations, which greatly reduces the design time and enables first-pass success.
Detection of Poor Wetting of Lead-Free Solder Bumps in Ball Grid Array Packages Using Laser Ultrasound Technique
Authors: Gong Jie , Ume I. Charles
Published: February 2012

A novel laser ultrasound and interferometer inspection system has been successfully applied to detect solder joint defects including missing, misaligned, open, and cracked solder bumps in flip chips, land grid array packages and chip capacitors. This system uses a pulsed Nd:YAG laser to induce ultrasound in the chip packages in the thermoelastic regime; it then measures the transient out-of-plane displacement response on the package surface using a laser interferometer. The quality of solder bumps is evaluated by analyzing the transient responses. In this paper, the application of this system is expanded to evaluate quality of lead-free solder bumps in ball grid array (BGA) packages; specifically BGA packages with poor wetting are used as test vehicles. Poor wetting not only decreases the mechanical strength of interconnection at the interface between the solder bumps and substrate, but also increases electrical resistance, which is a reliability issue. Causes of poor wetting vary from materials themselves to manufacturing process. Here, poor wetting of solder bumps were intentionally created by using an improper reflow profile. The transient out-of-plane displacement responses from these packages were compared with the responses from defect-free samples. Solder bumps with poor wetting were distinguished from the normal solder bumps by unusual correlation coefficient. Then, laser ultrasound inspection results are also compared with results from X-ray inspection and continuity test. Finally, the cross-section images were used to further confirm the existence of the poor wetting in samples with unusual correlation coefficient. It can be concluded that this laser-ultrasound system is capable of identifying the presence of poor wetting in BGA packages.
Some illustrative examples of the use of a spectral-element method in ocean acoustics
Authors: Cristini Paul , Komatitsch Dimitri
Published: February 2012

Some numerical results in the time domain obtained with the spectral-element method are presented in order to illustrate the high potential of this technique for modeling the propagation of acoustic waves in the ocean in complex configurations. A validation for a simple configuration with a known solution is shown, followed by some simulations of the propagation of acoustic waves over different types of ocean bottoms (fluid, elastic, and porous) to emphasize the wide variety of media that can be considered within the framework of this method. Finally, a movie illustrating upslope propagation over a viscoelastic wedge is presented and discussed.
Probing of laser-induced crack modulation by laser-monitored surface waves and surface skimming bulk waves
Authors: Ni Chen-Yin , Chigarev Nikolay , Tournat Vincent , Delorme Nicolas , Shen Zhong-Hua , Gusev Vitalyi E.
Published: February 2012

All-optical monitoring of the nonlinear motion of a surface-breaking crack is reported. Crack closing is induced by quasi-continuous laser heating, while Rayleigh surface acoustic pulses and bulk longitudinal surface skimming acoustic pulses are also generated and detected by lasers. By exploiting the strong dependence of the acoustic pulses reflection and transmission efficiency on the state—open or closed—of the contacts between the crack faces, the parametric modulation of ultrasonic pulses is achieved. It is observed that bulk acoustic waves skimming along the surface can be more sensitive to crack motion than Rayleigh surface waves.
Acoustical characterization of exploding hydrogen-oxygen balloons
Authors: Vernon Julia A. , Gee Kent L. , Macedone Jeffrey H.
Published: February 2012

Exploding hydrogen-oxygen balloons are popular chemistry demonstrations. Although initial research experimentally quantified potential hearing risk via analysis of peak levels [K. L. Gee et al., J. Chem. Educ. 87, 1039–1044 (2010)], further waveform and spectral analyses have been conducted to more fully characterize these impulsive noise sources. While hydrogen-only balloons produce inconsistent reactions and relatively low, variable levels, stoichiometrically mixed hydrogen-oxygen balloons produce consistent high-amplitude noise waveforms. Preliminary consideration is also given to the potential use of these exploding balloons in architectural acoustics applications.
Rapid perceptual learning of noise-vocoded speech requires attention
Authors: Huyck Julia Jones , Johnsrude Ingrid S.
Published: February 2012

Humans are able to adapt to unfamiliar forms of speech (such as accented, time-compressed, or noise-vocoded speech) quite rapidly. Can such perceptual learning occur when attention is directed away from the speech signal? Here, participants were simultaneously exposed to noise-vocoded sentences, auditory distractors, and visual distractors. One group attended to the speech, listening to each sentence and reporting what they heard. Two other groups attended to either the auditory or visual distractors, performing a target-detection task. Only the attend-speech group benefited from the exposure when subsequently reporting noise-vocoded sentences. Thus, attention to noise-vocoded speech appears necessary for learning.
Functional Supramolecular Polymers
Authors: Aida T. , Meijer E. W. , Stupp S. I.
Published: February 2012

Supramolecular Polymers Explained

While polymers are constructed from chemically bonded units, supramolecular polymers arise through reversible linkages, such as hydrogen bonding and electrostatic interactions. Recent advances in the field of supramolecular polymer science have moved from a fundamental understanding of assembly properties to the introduction of functionality, in order to exploit the particular features of this class of materials.

Aida
et al.

(p.
813
) review the specific features of supramolecular polymers that can lead to applications in a variety of fields, including: materials—in which processability and self-healing properties are of interest; biomedicine—in which the concerns are dynamic functionality and biodegradability; and hierarchical assembly and electronic systems—with an interest in unidirectionality of charge flow.
Structural Basis of TLR5-Flagellin Recognition and Signaling
Authors: Yoon Sung-il , Kurnasov Oleg , Natarajan Venkatesh , Hong Minsun , Gudkov Andrei V. , Osterman Andrei L. , Wilson Ian A.
Published: February 2012

Flagellin Takes Its Toll

The immune system recognizes bacterial infections by binding to conserved molecular fragments derived from the invading bacteria. Molecular mimics of these bacterial determinants have the potential to boost the immunogenicity of vaccines.

Yoon
et al.

(p.
859
) now report the crystal structure of the D1/D2 fragment of
Salmonella
flagellin, a protein critical for the motility of flagellated bacteria, with the ectodomain of zebrafish Toll-like receptor 5 (TLR5), the host receptor that binds to flagellin and signals the immune system to react. Two TLR5-flagellin heterodimers dimerized into a 2:2 tail-to-tail signaling complex. Mutational analysis and use of human TLR5 validated the signaling mechanism, which is conserved from zebrafish to humans.
Response to Comment on “A Diverse Assemblage of Late Cretaceous Dinosaur and Bird Feathers from Canadian Amber”
Authors: McKellar Ryan C. , Chatterton Brian D. E. , Wolfe Alexander P. , Currie Philip J.
Published: February 2012

Dove and Straker question our interpretations of plumage from Late Cretaceous Canadian amber. Although we are able to refute concerns regarding both specimen taphonomy and misidentification as botanical fossils, unequivocal assignment to either birds or dinosaurs remains impossible, as we stated originally. However, reported observations and their further refinement herein are insufficient to falsify the hypothesized dinosaurian origin for protofeathers.
Contemplating the First Plantae
Authors: Spiegel Frederick W.
Published: February 2012

What characterized the first photosynthetic eukaryotes?
Science and the Ontology of Belief
Grand Theories and Everyday Beliefs
Science, Philosophy, and Their Histories

by Wallace Matson

Oxford University Press, Oxford, 2011. 237 pp. $35, £22.50. ISBN 9780199812691.
Authors: Hughes P. William
Published: February 2012

Engaging both the history of philosophy and the development of science, Matson focuses on how we differentiate sense and nonsense.
Gene Losses in the Human Genome
Authors: Quintana-Murci Lluis
Published: February 2012

A comprehensive survey of the human genome reveals variations that disrupt protein-coding genes.
A Cold Editor Makes the Adaptation
Authors: Öhman Marie
Published: February 2012

Adaptation to cold temperature is mediated by RNA editing of a potassium channel in octopus neurons.
Dead Reckoning the Lethality of Bird Flu
Authors: Cohen Jon
Published: February 2012

On 2 February at the New York Academy of Sciences, Michael Osterholm and Peter Palese, both prominent influenza researchers, debated just how deadly the avian virus known as H5N1 is to humans.
Crohn's Disease Patients Have More IgG-Binding Fecal Bacteria than Controls
Authors: Harmsen Hermie J. M. , Pouwels Simon D. , Funke Anouk , Bos Nicolaas A. , Dijkstra Gerard
Published: February 2012

In Crohn's disease (CD), chronic gut inflammation leads to loss of mucosal barrier integrity. Subsequent leakage of IgG to the gut could produce an increase of IgG coating of intestinal bacteria. We investigated if there is more IgG coating in patients than in volunteers and whether this is dependent on the host IgG response or on the gut bacteria. Fecal and serum samples were obtained from 23 CD patients and 11 healthy volunteers. Both thein vivoIgG-coated fecal bacteria andin vitroIgG coating after serum addition were measured by flow cytometry and related to disease activity. The bacterial composition in feces was determined using fluorescencein situhybridization. The IgG-binding capacities ofEscherichia colistrains isolated from feces of patients and volunteers were assessed. The results showed that thein vivoIgG-coated fraction of fecal bacteria of patients was slightly larger than that of volunteers but significantly larger after incubation with either autologous or heterologous serum. This was dependent on the bacteria and independent of disease activity or the serum used. The presence of moreEnterobacteriaceaeand fewer faecalibacteria in patient feces was confirmed.E. coliisolates from patients bound more IgG than isolates from volunteers (P< 0.05) after the addition of autologous serum. Together, these results indicate that CD patients have more IgG-binding gut bacteria than healthy volunteers. We showed that the level of IgG coating depends on the bacteria and not on the serum used. Furthermore, CD patients have a strong specific immune response to their ownE. colibacteria.
Establishment of a Swiss Webster Mouse Model of Pneumonic Plague To Meet Essential Data Elements under the Animal Rule
Authors: Fellows Patricia , Lin Winston , Detrisac Carol , Hu Shu-Chieh , Rajendran Narayanan , Gingras Bruce , Holland Louis , Price Jessica , Bolanowski Mark , House Robert V.
Published: February 2012

A recombinant vaccine (rF1V) is being developed for protection against pneumonic plague. This study was performed to address essential data elements to establish a well-characterized Swiss Webster mouse model for licensing the rF1V vaccine using the FDA's Animal Rule. These elements include the documentation of challenge material characteristics, aerosol exposure parameters, details of the onset and severity of clinical signs, pathophysiological response to disease, and relevance to human disease. Prior to animal exposures, an evaluation of the aerosol system was performed to determine and understand the variability of the aerosol exposure system. Standardized procedures for the preparation ofYersinia pestischallenge material also were developed. The 50% lethal dose (LD50) was estimated to be 1,966 CFU using Probit analysis. Following the LD50determination, pathology was evaluated by exposing mice to a target LD99(42,890 CFU). Mice were euthanized at 12, 24, 36, 48, 60, and 72 h postexposure. At each time point, samples were collected for clinical pathology, detection of bacteria in blood and tissues, and pathology evaluations. A general increase in incidence and severity of microscopic findings was observed in the lung, lymph nodes, spleen, and liver from 36 to 72 h postchallenge. Similarly, the incidence and severity of pneumonia increased throughout the study; however, some mice died in the absence of pneumonia, suggesting that disease progression does not require the development of pneumonia. Disease pathology in the Swiss Webster mouse is similar to that observed in humans, demonstrating the utility of this pneumonic plague model that can be used by researchers investigating plague countermeasures.
Secondary Peritonitis Caused by Streptomyces viridis
Authors: Datta Priya , Arora Shilpa , Jain Ruby , Chander Jagdish , van de Sande Wendy
Published: February 2012

Streptomyces
organisms are soil inhabitants rarely causing nonmycetomic infections. We describe a case of secondary peritonitis caused by
Streptomyces viridis
in a chronic alcoholic patient who presented with fever, abdominal distension, and pain in the abdomen. The most likely source of infection was by inoculation through multiple paracenteses, done for treatment of ascites, before the patient came to our health care center. This is the second case report of
Streptomyces
peritonitis and the first case caused by
Streptomyces viridis
, which is usually found in the soil in our geographic region.
Corynebacterium Prosthetic Joint Infection
Authors: Cazanave Charles , Greenwood-Quaintance Kerryl E. , Hanssen Arlen D. , Patel Robin
Published: February 2012

Identification ofCorynebacteriumspecies may be challenging.Corynebacteriumspecies are occasional causes of prosthetic joint infection (PJI), but few data are available on the subject. Based on the literature,C. amycolatum,C. aurimucosum,C. jeikeium, andC. striatumare the most commonCorynebacteriumspecies that cause PJI. We designed a rapid PCR assay to detect the most common humanCorynebacteriumspecies, with a specific focus on PJI. A polyphosphate kinase gene identified using whole-genome sequence was targeted. The assay differentiates the antibiotic-resistant speciesC. jeikeiumandC. urealyticumfrom other species in a single assay. The assay was applied to a collection of humanCorynebacteriumisolates from multiple clinical sources, and clinically relevant species were detected. The assay was then tested onCorynebacteriumisolates specifically associated with PJI; all were detected. We also describe the first case ofC. simulansPJI.