The result of an operation between unaligned Series will have the union ofthe indexes involved. If a label is not found in one Series or the other, theresult will be marked as missing NaN. Being able to write code without doingany explicit data alignment grants immense freedom and flexibility ininteractive data analysis and research. The integrated data alignment featuresof the pandas data structures set pandas apart from the majority of relatedtools for working with labeled data.
Special consideration will need to be taken to determine microphone placement when monitoring workers who are wearing protective head gear such as abrasive blasting helmets or supplied air respirators. In many of these cases, the helmet/hood of this type of equipment would not be considered as a hearing protective device, and the microphone should be placed under the helmet/hood when measuring employee exposures. Care should be taken to ensure that the microphone does not contact surfaces inside the helmet/hood which may incur inaccurate noise measurements. Similarly, the microphone should also be positioned so that it is not located within any direct air streams such as from a supplied air respirator, which may also cause erroneous readings. Additional care may be necessary in running the dosimeter cable under any respirator or hood seals so that it does not interfere with such seals and as approved by the respirator manufacturer, as applicable. In some special cases, protective headwear such as abrasive blasting helmets may be considered as a secondary hearing protective device (earplugs worn under the helmet would be considered the primary hearing protective device). When considering the possibility for inclusion of the helmet as providing hearing protection, consultation with the manufacturer is necessary to determine the design, intent, and attenuation performance data associated with this scenario. If the helmet is determined to act as a hearing protector, the microphone should be placed outside the helmet when determining noise exposures and evaluating hearing protection worn by the employee. However, as previously mentioned, particular care is likely needed in order to protect the microphone in harsh environments; a wind screen would be necessary but for extremely harsh conditions it may not be feasible to position the microphone outside the hood/helmet. For questions related to assessing exposures and microphone placement associated with protective headwear and respirators, CSHOs should contact their regional OSHA office enforcement personnel or the OSHA Health Response Team for guidance, as necessary.
Compare the most recent annual audiogram with the baseline or reference audiogram to determine if an employee has an STS. If an STS is observed, review data for intervening years to determine when the STS occurred. The baseline audiogram is usually, but not always, the first audiogram. The baseline audiogram should be clearly documented and may be different for each ear. If a persistent STS is identified, the audiogram demonstrating the initial STS is often adopted as the revised baseline for future comparisons. Revising the baseline must be done by an audiologist, otolaryngologist (ENT physician) or other trained physician.
Agencies provide a heading for each part, subpart, section, and appendix that they are proposing to amend. The Amendment Part section identifies changes or additions to the CFR. The regulatory text of a document must fit into the current text of the CFR. It should precisely identify and describe the changes made to the CFR. The amendatory language uses standard terms to give specific instructions on how to change the CFR. It does not include a discussion of why the changes are made. If a document amends only certain sections within a CFR part, the authority citation for the part will set out as the first numbered item in the list of amendments for the part.
Head and neck squamous cell carcinomas (HNSCCs) develop from the mucosal epithelium in the oral cavity, pharynx and larynx and are the most common malignancies that arise in the head and neck (Fig. 1). The burden of HNSCC varies across countries/regions and has generally been correlated with exposure to tobacco-derived carcinogens, excessive alcohol consumption, or both. Increasingly, tumours that arise in the oropharynx are linked to prior infection with oncogenic strains of human papillomavirus (HPV), primarily HPV-16, and, to a lesser extent, HPV-18 and other strains1,2,3. As the most common oncogenic HPVs, HPV-16 and HPV-18, are covered by FDA-approved HPV vaccines, it is feasible that HPV-positive HNSCC could be prevented by successful vaccination campaigns worldwide. HNSCCs of the oral cavity and larynx are still primarily associated with smoking and are now collectively referred to as HPV-negative HNSCC. No screening strategy has proved to be effective, and careful physical examination remains the primary approach for early detection. Although a proportion of oral pre-malignant lesions (OPLs), which present as leukoplakia (white patches) or erythroplakia (red patches), progress to invasive cancer, the majority of patients present with advanced-stage HNSCC without a clinical history of a pre-malignancy. HNSCC of the oral cavity is generally treated with surgical resection, followed by adjuvant radiation or chemotherapy plus radiation (known as chemoradiation or chemoradiotherapy (CRT)) depending on the disease stage. CRT has been the primary approach to treat cancers that arise in the pharynx or larynx. HPV-positive HNSCC generally has a more favourable prognosis than HPV-negative HNSCC, and ongoing studies are testing the efficacy of therapeutic dose reduction (of both radiation and chemotherapy) in HPV-positive disease treatment. With the exception of early-stage oral cavity cancers (which are treated with surgery alone) or larynx cancers (which are amenable to surgery or radiation alone), treatment of the majority of patients with HNSCC requires multimodality approaches and thus multidisciplinary care. The epidermal growth factor receptor (EGFR; also known as HER1) monoclonal antibody cetuximab is approved by the FDA as a radiation sensitizer, alone or in combination with chemotherapy, for the treatment of patients with recurrent or metastatic disease4. Although inferior to cisplatin as a radiosensitizer in HPV-associated disease5,6, cetuximab is often used in cisplatin-ineligible patients. The immune checkpoint inhibitors pembrolizumab and nivolumab are approved by the FDA for treatment of cisplatin-refractory recurrent or metastatic HNSCC and pembrolizumab is approved as first-line therapy in patients who present with unresectable or metastatic disease7,8,9. Detailed molecular characterization as well as immune profiling of HNSCC suggests that incorporation of prognostic and predictive biomarkers into clinical management may overcome obstacles to targeted therapies and enable prolonged survival. In this Primer, we provide an overview of the types of HNSCC and their epidemiology, as well as the pathogenesis of each type and how this influences the management approach.
Advances in biotechnology, drug development, robotic surgery, radiotherapy approaches and molecular characterization of human cancers (including HNSCC) in the twenty-first century were expected to lead to improved outcomes for patients with HNSCC. However, despite these advances, outcomes have remained mostly unchanged for the past few decades, especially for HPV-negative HNSCC, and short-term and long-term treatment-associated morbidities are still substantial. Most patients still present with advanced-stage disease and are treated with platinum-based chemotherapy regimens that were approved by the FDA in 1978. Patients who survive their first HNSCC (especially HPV-negative HNSCC) remain at risk for development of a SPT of the upper aerodigestive tract for the rest of their lives. The requirement for multidisciplinary care (including, amongst others, head and neck surgery, radiation oncology, medical oncology, head and neck pathology, speech language pathology, nutrition, prosthodontics and oral medicine) coupled with the rarity of HNSCC in most countries, underscores our recommendation that all patients with HNSCC should be treated in centres with high case numbers and by experienced multidisciplinary teams. An analysis conducted in the USA employing the National Cancer Database showed that patients undergoing curative radiotherapy at facilities with high case numbers and academic centres showed higher survival than patients treated at centres with low case numbers234. Even when patients with HNSCC are treated in a multi-institutional chemoradiation clinical trial, the OS of those patients treated at centres that enrol more patients in trials in the USA was significantly longer than that of patients treated at institutions that enrol fewer patients235. In a pooled analysis of six randomized, controlled trials in Italy, patients with HNSCC treated at centres with high case numbers showed longer survival than patients treated at centres with low case numbers236. Despite improvements in treatment options, particularly the incorporation of immune checkpoint inhibitors into the standard of care, we also recommend that all patients with advanced, incurable HNSCC be offered the opportunity to participate in clinical trials that are based on a strong biological rationale. Table 1 lists trials of HNSCC treatments in the National Clinical Trials Network that are currently open for patient enrolment. Fortunately, numerous clinical trials are ongoing and precision medicine approaches are emerging.
When you track data in Excel spreadsheets, you create them with the human interface in mind. To make your spreadsheets easy to read, you might include things like titles, stacked headers, notes, maybe empty rows and columns to add white space, and you probably have multiple tabs of data too. 2b1af7f3a8