Intrinsically accurate sensing with an optomechanical accelerometer.

We demonstrate a microfabricated optomechanical accelerometer that is capable of percent-level accuracy without external calibration. To achieve this capability, we use a mechanical model of the device behavior that can be characterized by the thermal noise response along with an optical frequency comb readout method that enables high sensitivity, high bandwidth, high dynamic range, and SI-traceable displacement measurements. The resulting intrinsic accuracy was evaluated over a wide frequency range by comparing to a primary vibration calibration system and local gravity. The average agreement was found to be 2.1 % for the calibration system between 0.1 kHz and 15 kHz and better than 0.2 % for the static acceleration. This capability has the potential to replace costly external calibrations and improve the accuracy of inertial guidance systems and remotely deployed accelerometers. Due to the fundamental nature of the intrinsic accuracy approach, it could be extended to other optomechanical transducers, including force and pressure sensors.

A pyrosequencing protocol for rapid identification of SARS-CoV-2 variants.

Next-generation sequencing (NGS) is the primary method used to monitor the distribution and emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants around the world; however, it is costly and time-consuming to perform and is not widely available in low-resourced geographical regions. Pyrosequencing has the potential to augment surveillance efforts by providing information on specific targeted mutations for rapid identification of circulating and emerging variants. The current study describes the development of a reverse transcription (RT)-PCR-pyrosequencing assay targeting >65 spike protein gene (S) mutations of SARS-CoV-2, which permits differentiation of commonly reported variants currently circulating in the United States with a high degree of confidence. Variants typed using the assay included B.1.1.7 (Alpha), B.1.1.529 (Omicron), B.1.351 (Beta), B.1.375, B.1.427/429 (Epsilon), B.1.525 (Eta), B.1.526.1 (Iota), B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.621 (Mu), P1 (Gamma), and B.1.1 variants, all of which were confirmed by the NGS data. An electronic typing tool was developed to aid in the identification of variants based on mutations detected by pyrosequencing. The assay could provide an important typing tool for rapid identification of candidate patients for monoclonal antibody therapies and a method to supplement SARS-CoV-2 surveillance efforts by identification of circulating variants and novel emerging lineages.

Laser-based comparison calibration of laboratory standard microphones.

A precision laser-based comparison calibration method for laboratory standard microphones is described that uses reference microphones calibrated by the pressure reciprocity method. Electrical drive current and diaphragm velocity are measured while the microphones are driven as transmitters/sources of sound; the diaphragm velocity is measured using scanning laser Doppler vibrometry. Sensitivities determined using this method display very good agreement with those determined directly by reciprocity for seven such test microphones at 250 and 1000 Hz. At these frequencies, the expanded (coverage factor k = 2) uncertainties of this comparison calibration method for these microphones are ±0.05 dB.

Using the EPIDEM Model of Quality Improvement to Increase Value of BCR-ABL1 Tests.

Objectives: As pathologists and laboratorians, we can enhance patient care by promoting the appropriate ordering of diagnostic tests. Our goal was to improve the ordering of BCR-ABL1 tests by using the EPIDEM model of quality improvement. Methods: We applied the EPIDEM model, which emphasizes understanding local context, culture, and resources, to explore inappropriate BCR-ABL1 ordering, promote and implement a new reflexive testing strategy in-house, document and evaluate effectiveness, and make stepwise modifications. Results: Multiple quality improvement interventions correlated with cost savings and decreased total errors and incorrect orders for both BCR-ABL1 major and minor positive patients. Furthermore, our laboratory built stronger collaborative relationships with colleagues within and outside of pathology. Conclusions: Our molecular pathology laboratory successfully used the EPIDEM model of quality improvement to improve the ordering of BCR-ABL1 tests and promote better patient care by focusing on educational efforts and modification of laboratory workflow.

Adenocarcinoma of the cervix involving the fallopian tube mucosa: report of a case.

BACKGROUND: Fallopian tube involvement by cervical carcinoma has rarely been documented, with literature reports focusing primarily on squamous cell carcinoma. CASE PRESENTATION: In this report, we present the case of a 50 year old woman who presented with an abnormal Pap test with atypical squamous and glandular cells. A loop electrosurgical excision procedure (LEEP) was performed and led to the diagnosis of stage IB1 endocervical adenocarcinoma. Subsequent radical hysterectomy, bilateral salpingo-oophorectomy, and bilateral pelvic lymph node dissection showed a well-differentiated endocervical adenocarcinoma of usual type with superficial spread to the endometrium and right fallopian tube. The patient received no adjuvant therapy and has remained without evidence of disease. CONCLUSIONS: While the advent of more extensive fallopian tube sampling has led to increased discovery and discussion of fallopian tube involvement by metastatic carcinoma, its impact on treatment and prognosis remains to be seen.

Evaluation of clinical performance of a novel urine-based HPV detection assay among women attending a colposcopy clinic.

BACKGROUND: Human papillomavirus (HPV) testing in urine offers a convenient approach for cervical cancer screening but has previously suffered from limited clinical sensitivity. OBJECTIVES: We evaluated clinical performance of the prototype Trovagene HPV test, a novel polymerase chain reaction assay that targets the E1 region of the HPV genome and detects and amplifies short fragments of cell-free HPV DNA in urine. STUDY DESIGN: We conducted a pilot study among 72 women referred to colposcopy following abnormal screening. Participants provided a urine sample prior to clinician-collected cervical sampling and colposcopically-directed punch biopsy. Trovagene HPV test results on urine samples were compared with cervical and urine testing by Linear Array HPV Genotyping Test (LA-HPV) for detection of histologically-confirmed cervical precancerous lesions. RESULTS: There was high concordance between urine samples tested by the Trovagene HPV test and corresponding cervical (87.5%) and urine (81.9%) samples tested by LA-HPV. The Trovagene HPV test had high sensitivity (92.3% for detecting CIN2/3, and 100% for CIN3), comparable to LA-HPV testing on cervical samples (96.0% and 100%, respectively), and higher than LA-HPV testing on urine samples (80.8% and 90.0%, respectively). In this referral population, the specificity of the Trovagene urine HPV test was non-significantly lower (29% for CIN2/3 and 25% for CIN3) than corresponding estimates of LA-HPV testing on cervical (36% and 28%, respectively) and urine (42% and 38%, respectively) samples. CONCLUSIONS: This pilot study suggests that the Trovagene HPV test has high sensitivity for urine-based detection of cervical precancer and merits evaluation in larger studies.

Comparison of human papillomavirus detections in urine, vulvar, and cervical samples from women attending a colposcopy clinic.

While urine-based sampling for human papillomavirus (HPV) is being explored as a simple and noninvasive approach for cervical cancer screening, data comparing HPV genotyping in urine and those in cellular sampling of the cervix and vulva, and their correlation with rigorously confirmed cervical disease status, are sparse. We performed HPV genotyping on voided-urine and clinician-collected vulvar and cervical samples from 72 women undergoing colposcopy. Although urine-based HPV carcinogenic HPV detection was lower (58.3%) than cervical (73.6%) and vulvar (72.1%) detection (P = 0.05 and 0.07, respectively), the agreement of urine HPV with cervical and vulvar HPV was moderate (kappa = 0.55) and substantial (kappa = 0.62), respectively. Urine-based carcinogenic HPV detection had a clinical sensitivity of 80.8% (95% confidence interval [CI] = 60.7 to 93.5) and a specificity of 53.3% (95% CI = 37.9 to 68.3) for diagnosing cervical intraepithelial neoplasia grades 2/3 (CIN2/3) on histology; 90.0% of CIN3 was positive for urine HPV. The corresponding sensitivity and specificity values for vulvar sampling were 92% (95% CI = 74 to 99) and 40.5% (95% CI = 25.6 to 56.7), and those for cervical sampling were 96.2% (95% CI = 80.4 to 99.9) and 40% (95% CI = 25.7 to 55.7), respectively. HPV16 was the most common carcinogenic genotype detectable in 25% of urine, 33.8% of vulvar, and 31.9% of cervical samples overall, with prevalence increasing with cervical disease grade, regardless of the sampling method. Stronger cervical HPV PCR signal strengths were associated with increased frequency of urine HPV detection. In summary, the relatively lower detection rates but comparable clinical performance of urine-based HPV sampling underscore the need for larger studies to evaluate urine-based sampling for cervical cancer screening, epidemiologic studies, and postvaccination HPV disease surveillance.

The differential diagnosis of pilocytic astrocytoma with atypical features and malignant glioma: an analysis of 16 cases with emphasis on distinguishing molecular features.

Rare pilocytic astrocytomas (PA) have atypical histologic and clinicoradiologic features that raise the differential diagnosis of glioblastoma. Whether ancillary studies can supplement histopathologic examination in placing these cases accurately on the spectrum of WHO Grade I PA to higher-grade glioma is not always clear, partly because these cases are not common. Here, ten PAs with atypical clinicoradiologic and histologic features and six pediatric glioblastoma multiforme (pGBMs) were analyzed for BRAF V600E, IDH1, IDH2, and TP53 mutations. Ki-67, p53, and p16 protein expression were also examined by immunohistochemistry. BRAF-KIAA1549 fusion status was assessed in the PA subgroup. The rate of BRAF-KIAA1549 fusion was high in these PAs (5/7 tumors) including four extracerebellar examples. A single BRAF V600E mutation was identified in the fusion-negative extracerebellar PA of a very young child who succumbed to the disease. TP53 mutations were present only in malignant gliomas, including three pGBMs and one case designated as PA with anaplastic features (with consultation opinion of pGBM). IDH1 and IDH2 were wild type in all cases, consistent with earlier findings that IDH mutations are not typical in high-grade gliomas of patients ≤14 years of age. Immunohistochemical studies showed substantial overlap in Ki-67 labeling indices, an imperfect correlation between p53 labeling and TP53 mutation status, and complete p16 loss in only two pGBMs but in no PAs. These results suggest that (a) BRAF-KIAA1549 fusion may be common in PAs with atypical clinicoradiologic and histologic features, including those at extracerebellar sites, (b) BRAF V600E mutation is uncommon in extracerebellar PAs, and (c) TP53 mutation analysis remains a valuable tool in identifying childhood gliomas that will likely behave in a malignant fashion.

Reproducibility of linear array for human papillomavirus genotyping.

We conducted a Linear Array test/retest analysis using cytologic specimens from 198 women. A total of 67.2% of samples had the same human papillomavirus (HPV) types detected in both tests (type-specific positive agreement was 83.3% overall [Kappa = 0.9] and 86.8% for carcinogenic types [Kappa = 0.92]). Discordance was highest with a low hybridization signal strength. Overall, Linear Array was highly reproducible.

The role of co-factors in the progression from human papillomavirus infection to cervical cancer.

OBJECTIVE: Co-factors for cervical cancer, including oral contraceptive (OC) use, smoking and multiparity have been identified; however, the stage at which they act in cervical carcinogenesis is not clear. We compared established risk factors among women with CIN2 and CIN3 to evaluate the heterogeneity of these factors in precancer and also assessed their role during cervical carcinogenesis. METHODS: The current analysis included 2783 women with various stages of cervical disease who were enrolled in the Study to Understand Cervical Cancer Early Endpoints and Determinants (SUCCEED) and the Biopsy Study. Associations of co-factors within cervical precancer and at different stages of cervical carcinogenesis were estimated using logistic regression. RESULTS: Long-term OC use (10+years vs. never: OR=2.42, 95% CI: [1.13-5.15]), multiparity (3+ births vs. nulliparous: OR=1.54 [1.04-2.28]), smoking (ever vs. never: OR=1.95 [1.48-2.58]), and no Pap test in the previous five years (2.05 [1.32-3.17]) were positively associated with CIN3 compared to CIN2. We observed that long-term OC use, parity and smoking were associated with an increased risk of CIN3 compared to

Pyrosequencing of IDH1 and IDH2 mutations in brain tumors and non-neoplastic conditions.

The molecular profiling of brain tumors, including testing for MGMT promoter methylation and chromosome 1p/19q deletion, can provide both diagnostic and prognostic information that may guide treatment. Isocitrate dehydrogenase (IDH) mutation testing is a recent addition to this armamentarium of molecular pathology tools that similarly provides both diagnostic (eg, glioma vs. gliosis) and prognostic information. Herein, we describe a pyrosequencing-based approach to IDH1 and IDH2 mutation testing and its application to 139 neoplastic and non-neoplastic central nervous system specimens. Several technical issues encountered in the development of the assay, particularly with regard to the optimization of the sequencing reaction, are described. Mutations in IDH1 codon 132 or IDH2 codon 172 were identified in 31.2% of all screened cases and 46.2% of screened World Health Organization grade I to IV gliomas (n=93), with mutations arising exclusively in grade II to IV oligodendroglial, astrocytic, or mixed oligoastrocytic neoplasms. Examination of the relationship between the mutation status and other pertinent variables demonstrated a significant male predominance among IDH1-mutated gliomas, most notably in grade III to IV astrocytic neoplasms. A significant association between IDH1/IDH2 mutation and 1p/19q deletion was also seen (Kendall τ coefficient=0.26, P=0.018), although several cases with 1p/19q deletion were IDH1/IDH2 wild type.

Human papillomavirus load measured by Linear Array correlates with quantitative PCR in cervical cytology specimens.

Carcinogenic human papillomavirus (HPV) infections are necessary causes of most anogenital cancers. Viral load has been proposed as a marker for progression to cancer precursors but has been confirmed only for HPV16. Challenges in studying viral load are related to the lack of validated assays for a large number of genotypes. We compared viral load measured by Linear Array (LA) HPV genotyping with the gold standard, quantitative PCR (Q-PCR). LA genotyping and Q-PCR were performed in 143 cytology specimens from women referred to colposcopy. LA signal strength was measured by densitometry. Correlation coefficients and receiver operating characteristic (ROC) analyses were used to evaluate analytical and clinical performance. We observed a moderate to strong correlation between the two quantitative viral load measurements, ranging from an R value of 0.61 for HPV31 to an R value of 0.86 for HPV52. We also observed agreement between visual LA signal strength evaluation and Q-PCR. Both quantifications agreed on the disease stages with highest viral load, which varied by type (cervical intraepithelial neoplasia grade 2 [CIN2] for HPV52, CIN3 for HPV16 and HPV33, and cancer for HPV18 and HPV31). The area under the curve (AUC) for HPV16 Q-PCR at the CIN3 cutoff was 0.72 (P = 0.004), and the AUC for HPV18 LA at the CIN2 cutoff was 0.78 (P = 0.04). Quantification of LA signals correlates with the current gold standard for viral load, Q-PCR. Analyses of viral load need to address multiple infections and type attribution to evaluate whether viral load has clinical value beyond the established HPV16 finding. Our findings support conducting comprehensive studies of viral load and cervical cancer precursors using quantitative LA genotyping data.

Clinical and pathological heterogeneity of cervical intraepithelial neoplasia grade 3.

OBJECTIVE: Cervical intraepithelial neoplasia grade 3 (CIN3), the immediate cervical cancer precursor, is a target of cervical cancer prevention. However, less than half of CIN3s will progress to cancer. Routine treatment of all CIN3s and the majority of CIN2s may lead to overtreatment of many lesions that would not progress. To improve our understanding of CIN3 natural history, we performed a detailed characterization of CIN3 heterogeneity in a large referral population in the US. METHODS: We examined 309 CIN3 cases in the SUCCEED, a large population-based study of women with abnormal cervical cancer screening results. Histology information for 12 individual loop electrosurgical excision procedure (LEEP) segments was evaluated for each woman. We performed case-case comparisons of CIN3s to analyze determinants of heterogeneity and screening test performance. RESULTS: CIN3 cases varied substantially by size (1-10 LEEP segments) and by presentation with concomitant CIN2 and CIN1. All grades of CINs were equally distributed over the cervical surface. In half of the women, CIN3 lesions were found as multiple distinct lesions on the cervix. Women with large and solitary CIN3 lesions were more likely to be older, have longer sexual activity span, and have fewer multiple high risk HPV infections. Screening frequency, but not HPV16 positivity, was an important predictor of CIN3 size. Large CIN3 lesions were also characterized by high-grade clinical test results. CONCLUSIONS: We demonstrate substantial heterogeneity in clinical and pathological presentation of CIN3 in a US population. Time since sexual debut and participation in screening were predictors of CIN3 size. We did not observe a preferential site of CIN3 on the cervical surface that could serve as a target for cervical biopsy. Cervical cancer screening procedures were more likely to detect larger CIN3s, suggesting that CIN3s detected by multiple independent diagnostic tests may represent cases with increased risk of invasion.

HPV16 variant lineage, clinical stage, and survival in women with invasive cervical cancer.

BACKGROUND: HPV16 variants are associated with different risks for development of CIN3 and invasive cancer, although all are carcinogenic. The relationship of HPV 16 variants to cancer survival has not been studied. METHODS: 155 HPV16-positive cervical cancers were categorized according to European and non-European variant patterns by DNA sequencing of the E6 open reading frame. Clinico-pathologic parameters and clinical outcome were collected by chart review and death registry data. RESULTS: Of the 155 women (mean age 44.7 years; median follow-up 26.7 months), 85.2% harbored European variants while 14.8% had non-European sequences. HPV16 variants differed by histologic cell type (p = 0.03) and stage (1 vs. 2+; p = 0.03). Overall, 107 women (68.0%) were alive with no evidence of cancer, 42 (27.1%) died from cervical cancer, 2 (1.3%) were alive with cervical cancer, and 4 (2.6%) died of other causes. Death due to cervical cancer was associated with European variant status (p < 0.01). While 31% of women harboring tumors with European variants died from cervical cancer during follow-up, only 1 of 23 (4.4%) non-European cases died of cancer. The better survival for non-European cases was partly mediated by lower stage at diagnosis. CONCLUSIONS: Overall, invasive cervical cancers with non-European variants showed a less aggressive behavior than those with European variants. These findings should be replicated in a population with more non-European cases.

Comparison of 2 line blot assays for defining HPV genotypes in oral and oropharyngeal squamous cell carcinomas.

Patients with invasive oral and oropharyngeal squamous cell carcinomas infected with human papillomaviruses (HPV) demonstrate improved survival. HPV detection in tumors may assist in risk stratification of patients and in guiding optimum treatment. Two reverse line blot assays [Linear Array (LA) and INNO-LiPA (LiPA)] were evaluated for detection of HPV genotypes in paraffin-embedded biopsies. Overall, 82.4% of 131 biopsies were HPV+ by LiPA versus 61.1% by LA (κ = 0.32). Completely concordant results were observed in 52.7% of cases: 18 negative and 51 with exactly the same genotype(s). An additional 13 cases had partial agreement. These 82 completely or partially concordant cases revealed a high rate of HPV positivity (78.0%), primarily involving HPV16 (90.6%). HPV+ tumors occurred preferentially in the oropharynx, especially tonsils, with trends for male patients and poor differentiation. Significant differences in these associations were found when LA and LiPA results were analyzed independently. No relationships were found between tumor HPV status and tobacco or alcohol use.

HPV genotype distribution in oral and oropharyngeal squamous cell carcinoma using seven in vitro amplification assays.

BACKGROUND: Molecular and epidemiologic evidence indicates that human papillomavirus (HPV) is involved in the etiology of oral and oropharyngeal squamous cell carcinomas (SCCs). HPV(+) tumors appear to be clinically distinct from HPV(-) tumors, conferring improved survival outcomes for patients. Determination of the HPV status of tumors may assist in patient risk-stratification and ultimately guide optimum treatment. The primary aim of this study was to examine the distribution of HPV in oral and oropharyngeal SCCs as assessed using seven different in vitro amplification assays. The secondary aim was to correlate the distribution of HPV in tumors with clinical and demographic patient data. MATERIALS AND METHODS: Sixty-eight invasive oral/oropharyngeal SCCs were tested for HPV using four laboratory-developed PCR assays for HPV16 or 18 and three commercial tests, INNO-LiPA® HPV Genotyping Extra (Innogenetics), Linear Array® HPV Genotyping Test (Roche Diagnostics), and Invader® HPV16/18 ASRs (Hologic Corp.). RESULTS: Consensus results between tests revealed that 71.9% of tumors were HPV(+), primarily with HPV16 (63.2%). Other genotypes were uncommon and generally occurred coincidently with HPV16. HPV-positivity was significantly higher in oropharyngeal tumors (76.9%), particularly of the tonsils (91.7%), versus oral cavity tumors (20.0%). HPV(+) tumors occurred in younger patients (average 54.4 years versus 61.1 years) and were significantly associated with lower histological differentiation (poorly, 100.0%; moderately, 65.6%; well-differentiated, 42.9%). CONCLUSION: A high rate of HPV-positivity, especially involving HPV16, occurred in oropharyngeal tumors, with a lower rate in oral cavity SCCs; however, solitary infections with HPV18, 33 or 45 in a minority of cases signified the potential oncogenicity of these additional genotypes and the likely need to screen for these less common genotypes in clinical specimens.

Comparison of molecular methods for detection of HPV in oral and oropharyngeal squamous cell carcinoma.

Substantial molecular evidence exists to implicate human papillomavirus (HPV) in the pathogenesis of a subset of oral and oropharyngeal squamous cell carcinomas. Several studies have shown that HPV-associated oral/oropharyngeal tumors differ etiologically, biologically, and clinically from those that lack the virus. HPV infection confers a significant survival benefit; therefore, HPV detection in tumors could be used to risk-stratify patients and drive optimum treatment strategies. We explored the clinical utility of 6 polymerase chain reaction (PCR)-based or signal amplification-based methods in the detection of HPV in 68 invasive oral/oropharyngeal SSCs and 10 reactive tonsil specimens. Agreement for HPV16 results among the 5 different assays capable of detecting this genotype was substantial (multirater κ=0.72). Only moderate agreement was noted for the 3 assays capable of detecting HPV18 (multirater κ=0.43). HPV results for each assay were evaluated relative to a "majority" HPV result derived from the results of all the detection methods. An HPV16 E6 PCR assay showed the highest concordance with adjudicated consensus HPV16 results (98.7%; κ=0.97), followed by the TaqMan (93.4%; κ=0.87), Linear Array (92.1%; κ=0.84), and E7 PCR (92.1%; κ=0.84) assays, all of which had agreements exceeding 90%, whereas the HPV16/18 Invader assay was lower (85.5%; κ=0.71). The presence of high-risk HPV in a minority of "normal" tonsillar tissues may confound assessment of the virus in oral/oropharyngeal squamous cell carcinoma biopsies using in vitro amplification methods.

MEMS Young's Modulus and Step Height Measurements With Round Robin Results.

This paper presents the results of a microelectromechanical systems (MEMS) Young's modulus and step height round robin experiment, completed in April 2009, which compares Young's modulus and step height measurement results at a number of laboratories. The purpose of the round robin was to provide data for the precision and bias statements of two \ related Semiconductor Equipment and Materials International (SEMI) standard test methods for MEMS. The technical basis for the test methods on Young's modulus and step height measurements are also provided in this paper. Using the same test method, the goal of the round robin was to assess the repeatability of measurements at one laboratory, by the same operator, with the same equipment, in the shortest practical period of time as well as the reproducibility of measurements with independent data sets from unique combinations of measurement setups and researchers. Both the repeatability and reproducibility measurements were done on random test structures made of the same homogeneous material. The average repeatability Young's modulus value (as obtained from resonating oxide cantilevers) was 64.2 GPa with 95 % limits of ± 10.3 % and an average combined standard uncertainty value of 3.1 GPa. The average reproducibility Young's modulus value was 62.8 GPa with 95 % limits of ± 11.0 % and an average combined standard uncertainty value of 3.0 GPa. The average repeatability step height value (for a metal2-over-poly1 step from active area to field oxide) was 0.477 µm with 95 % limits of 7.9 % and an average combined standard uncertainty value of 0.014 µm. The average reproducibility step height value was 0.481 µm with 95 % limits of ± 6.2 % and an average combined standard uncertainty value of 0.014 µm. In summary, this paper demonstrates that a reliable methodology can be used to measure Young's modulus and step height. Furthermore, a micro and nano technology (MNT) 5-in-1 standard reference material (SRM) can be used by industry to compare their in-house measurements using this methodology with NIST measurements thereby validating their use of the documentary standards.

Multiple human papillomavirus genotype infections in cervical cancer progression in the study to understand cervical cancer early endpoints and determinants.

Determining the causal attribution of human papillomavirus (HPV) genotypes to cervical disease is important to estimate the effect of HPV vaccination and to establish a type spectrum for HPV-based screening. We analyzed the prevalence of HPV infections and their attribution to cervical disease in a population of 1,670 women referred to colposcopy for abnormal cytology at the University of Oklahoma. HPV genotyping was performed from cytology specimens using the Linear Array assay that detects 37 HPV genotypes. We used different methods of type attribution to revised cervical disease categories. We found very high prevalence of multiple HPV infections with up to 14 genotypes detected in single specimens. In all disease categories except for cancers, there was a significant trend of having more infections at a younger age. We did not see type interactions in multiple genotype infections. HPV16 was the most frequent genotype at all disease categories. Based on different attribution strategies, the attribution of vaccine genotypes (6, 11, 16, 18) ranged from 50.5 to 67.3% in cancers (n = 107), from 25.6 to 74.8% in CIN3 (n = 305), from 15.2 to 52.2% in CIN2 (n = 427), and from 6.6 to 26.0% in

Controlled formation and resistivity scaling of nickel silicide nanolines.

We demonstrate a top-down method for fabricating nickel mono-silicide (NiSi) nanolines (also referred to as nanowires) with smooth sidewalls and line widths down to 15 nm. Four-probe electrical measurements reveal that the room temperature electrical resistivity of the NiSi nanolines remains constant as the line widths are reduced to 23 nm. The resistivity at cryogenic temperatures is found to increase with decreasing line width. This finding can be attributed to electron scattering at the sidewalls and is used to deduce an electron mean free path of 6.3 nm for NiSi at room temperature. The results suggest that NiSi nanolines with smooth sidewalls are able to meet the requirements for implementation at the 22 nm technology node without degradation of device performance.