Search

Human cytomegalovirus (HCMV) is an important opportunistic pathogen in allogeneic haematopoietic stem cell transplant (HSCT) recipients. High-throughput sequencing of target-enriched libraries was performed to characterise the diversity of HCMV strains present in this high-risk group. Forty-four HCMV-DNA-positive plasma specimens (median viral input load 321 IU per library) collected at defined time points from 23 HSCT recipients within 80 days of transplantation were sequenced. The genotype distribution for 12 hypervariable HCMV genes and the number of HCMV strains present (i.e. single- vs. multiple-strain infection) were determined for 29 samples from 16 recipients. Multiple-strain infection was observed in seven of these 16 recipients, and five of these seven recipients had the donor (D)/recipient (R) HCMV-serostatus combination D + R + . A very broad range of genotypes was detected, with an intrahost composition that was generally stable over time. Multiple-strain infection was not associated with particular virological or clinical features, such as altered levels or duration of antigenaemia, development of acute graft-versus-host disease or increased mortality. In conclusion, despite relatively low viral plasma loads, a high frequency of multiple-strain HCMV infection and a high strain complexity were demonstrated in systematically collected clinical samples from this cohort early after HSCT. However, robust evaluation of the pathogenic role of intrahost viral diversity and multiple-strain infection will require studies enrolling larger numbers of recipients. Supplementary Information The online version contains supplementary material available at 10.1007/s00430-021-00722-5.

We are introducing a new family of fluorine-free photoacid generators (PAGs) for use in 193 nm lithography. These PAGs are based on percyano-substituted cyclopentadienide anions and do not contain sulfonate groups. PAGs with these weakly coordinating anions generate photoacids of a similar strength as perfluroalkylsulfonic acids. Triphenylsulfonium pentacyanocyclopentadienide (TPS CN5) can be synthesized from inexpensive precursors, is stable in the presence of strong acids, has a low optical density at 193 nm and is well soluble in typical resist solvents. The performance of model resists formulated with TPS CN5 approaches that of commercially offered photoresists for the 32 nm node.

The combination of immersion lithography and reticle enhancement techniques (RETs) has extended 193nm lithography into the 45nm node and possibly beyond. In order to fulfill the tight pitch and small critical dimension requirements of these future technology nodes, the performance of 193nm resist materials needs to further improve. In this paper, we have systematically studied a variety of acidic functionalities in an effort to improve the dissolution properties of 193nm resists. The hexafluoroalcohol (HFA) and fluorosulfonamide (FSM) are found to be most effective in eliminating the swelling behavior associated with typical 193nm methacrylate resists. The HFA and FSM groups are highly transparent at 193nm. High performance 193nm resists are developed with the HFA and FSM acidic groups. Compared to the HFA group, the trifluoromethyl sulfonamide (TFSM) functionality has a lower pKa value and contains less fluorine atoms. Polymers containing the TFSM functionality have exhibited improved dissolution properties and better etch resistance than their HFA counterparts. Resists based on the FSM-containing polymers have shown superior lithographic performance for line, trench and contact hole levels under the 45nm node exposure conditions. In addition, FSM resists have also demonstrated excellent bright field and dark field compatibility and thereby make it possible to use one resist for both bright field and dark field level applications. Finally, to alleviate the adverse impact of the fluorine content in the etch resistance of the 193nm resists, we have also evaluated a non-fluorinated acidic functional alternative-naphthol.

This paper reviews IBM's 193 nm resist development efforts, placing an emphasis on the systems employing fluoroalcohol as an acidic group. Polymethacrylates were initially selected as a platform for their good transparency at 193 nm and then the emphasis on dry etch resistance prompted the work on all-norbornene systems. Carboxylic acid was employed in these resist systems as an acid group, which resulted in significant swelling during aqueous base development. Replacement of the carboxylic acid with fluoroalcohol has produced second generation 193 nm resist systems, the good dissolution behavior of which is offered by the fluoroalcohol group. The fluoroalcohol-based 193 nm resists in this study include cycloolefin-SO2, all-norbornene, trifluoromethylacrylate-norbornene (and vinyl ether), methacrylate, and silsesquioxane systems. Copyright © 2006 John Wiley & Sons, Ltd.

We have designed and developed a variety of hexafluoroalcohol (HFA) pendant methacrylate monomers and the corresponding imaging polymers for ArF lithography. It was found that HFA side chains are critical for "swelling free" dissolution properties for the polymers and resists. Through the incorporation of HFA functionalities, ArF resists can obtain linear dissolution properties commonly seen in 248nm ESCAP resists. These improved dissolution properties in turn significantly reduce PEB sensitivity of higher activation protecting group (e.g., methyladamantanyl) based ArF resists. We have also showed that the fluorine impact on etch rates can be modulated through the insertion of cyclic and aliphatic spacers between the main chain and the HFA functionalities. The key application space for HFA-methacrylate resists appears to be trench level lithography. It was also demonstrated that these HFA materials are compatible with immersion lithography and result in dramatically improved process windows for iso trench features, in addition to other lines/space features.

Extensive full-atomistic molecular dynamics simulations are performed to study the self-organization of C60-fullerene dyad molecules in water, namely phenyl-C61-butyric acid methyl ester and fulleropyrrolidines, which have two elements of ordering, the hydrophobic fullerene cage and the hydrophilic/ionic group. While pristine fullerene or phenyl-C61-butyric acid methyl ester forms spherical droplets in order to minimize the surface tension, the amphiphilic nature of charged solute molecules leads to the formation of supramolecular assemblies having cylindrical shape driven by charge repulsion between the ionic groups located on the surface of the aggregates. We show that formation of non-spherical micelles is the geometrical consequence if the fullerene derivatives are considered as surfactants where the ionized groups are only hydrophilic unit. The agglomeration behavior of fullerenes is evaluated by determining sizes of the clusters, solvent accessible surface areas, and shape parameters. By changing the size of the counterions from chloride over iodide to perchlorate we find a thickening of the cylinder-like structures which can be explained by stronger condensation of larger ions and thus partial screening of the charge repulsion on the cluster surface. The reason for the size dependence of counterion condensation is the formation of a stronger hydration shell in case of small ions which in turn are repelled from the fullerene aggregates. Simulations are also in good agreement with the experimentally observed morphologies of decorated C60-nanoparticles.

This paper will describe the strengths and unique challenges of building 193nm resists from acrylic polymers and cyclic olefin polymers. In particular, cyclic olefin (alternating) copolymer synthesis and properties will be discussed.

A revealing analysis of triplexer effects on harmonic load-pull measurements is conducted in the context of assessing the ability of the test system to maintain tuning independency between the fundamental and harmonic tuning ports. The type of triplexers studied consist of four port passive devices with one common port and 3 output ports; namely, fundamental, second harmonic and third harmonic tuning ports. It is shown in this work that very good isolation between the harmonic ports and very good rejection at unwanted frequencies between the common and each of the harmonic ports are of prime importance in establishing tuning independency. Influence of non-ideal isolation/rejection and lossiness of the triplexer on harmonic load pull applications will be presented, based on experimental results and analytical simulation of a commercially available load pull system and triplexer from Maury Microwave. For the analytical work, Agilent Technology's Advanced Design System-2002 was used along with a model for the triplexer, based on a signal flow graph analysis. Plots were generated to describe effects of non-ideal isolations, rejection, and loss on tuning independency and achievable max-reflection coefficient at the amplifier output plane. Discussions and simulation results are presented concerning compromise on isolations/rejections specifications for the triplexer to the extent that tuning independency is being maintained. As one example of the types of conclusions this model allows, it was determined that deviations in fundamental reflection coefficient with harmonic tuning are below measurement repeatability for a combined harmonic-to-common port rejection of 59 dB and harmonic-to-fundamental port isolation of 50dB. The experimentally examined triplexer provides performance exceeding these limits, with a margin. The authors believe that this is the first analysis of its kind providing a detailed consideration of non-ideal triplexers as used in harmonic load-pull measurement systems.

The 45-nm technology, called 12S and developed for IBM POWER7®, is an extremely robust and versatile technology platform that allows for a rich set of features that include embedded dynamic random access memory (DRAM), performance and dense static RAM (SRAM), a trench-based decoupling capacitor, a comprehensive device menu, and a high-performance hierarchical back-end interconnect scheme, all built on a silicon-on-insulator (SOI) substrate. Embedded DRAM was implemented for production in high-performance SOI for the first time and allowed us to leapfrog two generations of conventional SRAM densities. Immersion lithography was also employed for the first time in 45-nm IBM products. Our 45-nm design point represents a judicious leverage of silicon oxynitride dielectrics, scaled device technology, and rich features to yield chip-level performance enhancement of more than 50%, compared with our 65-nm node at comparable or less power. This paper describes the salient features of this technology node, the process architecture, the device design rationale, and the process design interactions.

An 86-year-old man with previous normal renal function was hospitalized because of renal insufficiency. He had a long history of atherosclerotic heart disease, mild hypertension and pulmonary embolism, requiring anticoagulant therapy. In view of the normal-sized kidneys and absence of casts in the urinary sediment, a diagnosis of atheroembolic renal disease was made. The patient's renal function deteriorated, but he refused hemodialysis. Death occurred within a few weeks. At autopsy, severe aortic atherosclerosis was observed and atheroembolic renal disease was confirmed as the cause of renal failure. Occasionally, renal failure can be the sole manifestation of spontaneous atheroembolic disease. This possibility should be considered if the physician is called upon to establish the diagnosis when renal insufficiency develops in atherosclerotic patients.

A prospective trial of warfarin and dipyridamole was performed in patients with membranoproliferative glomerulonephritis. Eighteen completed either a control or treatment year, and 13 completed both a control and treatment year. To obviate the bias of excluding control patients who had renal failure after one year, both an unpaired and a paired analysis were performed. The unpaired analysis compared 10 patients followed for an initial control year with eight patients receiving treatment first. Renal function remained stable over the year in the treated group, but worsened in the control group. Slopes of regression lines for reciprocal serum creatinine values were significantly different between groups (p less than 0.025). Urine protein excretion also decreased in the treated group. Four of 10 control patients had a two-fold increase in serum creatinine levels, but no treatment patient did. In the paired crossover analysis, significant differences in renal function were detected between control and treatment years in six patients whose renal function significantly changed over one of the years. In every instance, there was better preservation of renal function in the treatment year. Urinary protein also decreased significantly over the treatment year compared with the control year. Bleeding was the most frequent complication. These data suggest that warfarin and dipyridamole have a beneficial effect on renal function in membranoproliferative glomerulonephritis.

Occurrence of lactic acidosis with adequate tissue oxygenation (type B lactic acidosis) has been described in association with leukemia, lymphoma and a single case of Hodgkin's disease. No cases of this type have been reported in association with solid tumors. A case of type B lactic acidosis in a woman with rapidly progressing metastatic breast carcinoma is described.

Two male patients with Goodpasture's syndrome manifesting as severe pulmonary hemorrhage with minimal renal abnormalities are described. Both patients had microscopic hematuria with normal renal function, and one had transient proteinuria. Renal glomerular histology was normal and electron microscopic findings revealed no electron-dense deposits, but immunofluorescence of immunoglobulin G (IgG) was positive in a linear fashion along glomerular capillary basement membranes in both patients. Pulmonary hemorrhage was arrested following prednisone therapy, and both patients have normal pulmonary and renal function at five and 13 months of follow-up. The literature on patients with Goodpasture's syndrome, pulmonary hemorrhage and normal renal function with minimal proteinuria is reviewed. It is suggested that a subset of patients with Goodpasture's sybdrome have pulmonary hemorrhage as their major manifestation. Since prednisone seems to have an apparent beneficial effect on pulmonary hemorrhage, and relatively good prognosis, this diagnosis should be considered in patients with idiopathic pulmonary hemorrhage.

We report the first three cases of peritonitis due to the fungus Coccidioides immitis occurring during continuous ambulatory peritoneal dialysis (CAPD). At the time of diagnosis, none of the patients had evidence of active infection outside of the peritoneal cavity. Clues suggesting the diagnosis including a previous history of pulmonary coccidioidomycosis, an excess number of eosinophils in the peritoneal fluid, and failure to respond to therapy directed against bacteria. C immitis in peritoneal fluid was more readily isolated on specific fungal culture media than on routine bacterial culture media. In no instances did potassium hydroxide (KOH) preparations of the fluid reveal fungi. Coccidioidal peritonitis during CAPD appears to be a localized form of extrapulmonary coccidioidomycosis that has a relatively benign course once the peritoneal catheter is removed.

A patient with bilateral involvement of the kidneys with diffuse histiocytic lymphoma associated with renal failure is presented. This case report provides an example of the abscopal effect. Although only one kidney received radiation therapy, both kidneys were shown to respond to this treatment.