Editorial for the Special Issue on Flexible Micromanipulators and Micromanipulation

The field of micromanipulation is rapidly growing and evolving thanks to advancements in microfabrication technologies and the increased demand for precise and accurate manipulation of microscale objects [...].

Direct Kinetostatic Analysis of a Gripper with Curved Flexures

Micro-electro-mechanical-systems (MEMS) extensively employed planar mechanisms with elastic curved beams. However, using a curved circular beam as a flexure hinge, in most cases, needs a more sophisticated kinetostatic model than the conventional planar flexures. An elastic curved beam generally allows its outer sections to experience full plane mobility with three degrees of freedom, making complex non-linear models necessary to predict their behavior. This paper describes the direct kinetostatic analysis of a planar gripper with an elastic curved beam is described and then solved by calculating the tangent stiffness matrix in closed form. Two simplified models and different contributions to derive their tangent stiffness matrices are considered. Then, the Newton-Raphson iterative method solves the non-linear direct kinetostatic problem. The technique, which appears particularly useful for real-time applications, is finally applied to a case study consisting of a four-bar linkage gripper with elastic curved beam joints that can be used in real-time grasping operations at the microscale.

Dynamic Model of a Conjugate-Surface Flexure Hinge Considering Impacts between Cylinders

A dynamic model of a Conjugate-Surface Flexure Hinge (CSFH) has been proposed as a component for MEMS/NEMS Technology-based devices with lumped compliance. However, impacts between the conjugate surfaces have not been studied yet and, therefore, this paper attempts to fill this gap by proposing a detailed multibody system (MBS) model that includes not only rigid-body dynamics but also elastic forces, friction, and impacts. Two models based on the Lankarani-Nikravesh constitutive law are first recalled and a new model based on the contact of cylinders is proposed. All three models are complemented by the friction model proposed by Ambrosìo. Then, the non-smooth Moreau time-stepping scheme with Coulomb friction is described. The four models are compared in different scenarios and the results confirm that the proposed model outcomes comply with the most reliable models.

Dynamic assessment of the risk of airborne viral infection

This paper applies the Rudnick and Milton method through the dynamic evaluation of the probability of airborne contagion, redefining all parameters and variables in discretized form. To adapt the calculation of the risk of contagion to real needs, scenarios are used to define the presence of people, infected subjects, the hourly production of the quanta of infection, and the calculation of the concentration of CO₂ produced by exhalation in the air. Three case studies are discussed: a school, an office, a commercial activity. Complex scenarios include environmental sanitization, a variable number of people, and the possibility of simulating work shifts. The dynamic evaluation of the quanta of infection is also estimated, not foreseen by the Rudnick and Milton model, and involves updating the average values of the equivalent fraction of the indoor air with an improvement in the accuracy of the calculation due to the reduction of improper peaks of the stationary variables.

Thyroid hemiagenesis associated with multinodular goiter and Hashimoto's thyroiditis

Thyroid hemiagenesis is a rare congenital abnormality in which one of the thyroid lobes is not developed. It can be associated with various thyroid diseases, such as Grave's disease, nodular goiter and thyroid neoplasm, rarely with hyperparathyroidism. We report a case of a 50-year old woman with left thyroid lobe agenesis diagnosed by ultrasonography and scintigraphy. Right thyroidectomy was performed and the histopathological examination showed diffuse hyperplasia, multinodular goiter and Hashimoto's thyroiditis. To our knowledge, this is the first description of multinodular goiter and Hashimoto's thyroiditis in a patient with thyroid hemiagenesis.

Dynamics of a high-performance motorcycle by an advanced multibody/control co-simulation

The present work aims at the development of an advanced control system implemented through Adams/View-Matlab/Simulink co-simulation for a high-performance motorcycle dynamics study. In particular, the purpose of this study is to create a model able to consider several aspects of the rider–motorbike dynamic simulation and its control system, generally treated separately in the literature, making also use of an original and accurate modelling of the rider. From a previous multi-body model of motorcycle/virtual rider, developed by the authors, a flexible tool is created to simulate system dynamics to follow any trajectory at a prescribed velocity profile. Considering high-performance motorcycle dynamics are greatly influenced by the rider’s weight, his movements have been accurately replicated to obtain the most realistic results. To simulate the passive impedance of rider’s arms, a torque was applied to the steering as per the literature. The aerodynamic force was modelled as a function of kinematics variables and rider’s posture. The control system is very flexible and adaptable to different manoeuvres realistically reproducing engine and braking performance, steering torque and rider movements. Numerical results show that the control system can accurately direct the motorcycle/rider system along an entire lap of the Monza circuit, following a desired path at a given velocity profile. The model developed allows a complete view of the motorbike-rider dynamic behaviour thus being useful during both design phase and set-up, with a considerable saving in terms of both cost and time; it can also evaluate the influence on the system dynamics of riders with different anatomical characteristics and driving styles.

Individual patient data systematic review and meta-analysis of optic nerve sheath diameter ultrasonography for detecting raised intracranial pressure: protocol of the ONSD research group

BACKGROUND

The purpose of the optic nerve sheath diameter (ONSD) research group project is to establish an individual patient-level database from high quality studies of ONSD ultrasonography for the detection of raised intracranial pressure (ICP), and to perform a systematic review and an individual patient data meta-analysis (IPDMA), which will provide a cutoff value to help physicians making decisions and encourage further research. Previous meta-analyses were able to assess the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP but failed to determine a precise cutoff value. Thus, the ONSD research group was founded to synthesize data from several recent studies on the subject and to provide evidence on the diagnostic accuracy of ONSD ultrasonography in detecting raised ICP.

METHODS

This IPDMA will be conducted in different phases. First, we will systematically search for eligible studies. To be eligible, studies must have compared ONSD ultrasonography to invasive intracranial devices, the current reference standard for diagnosing raised ICP. Subsequently, we will assess the quality of studies included based on the QUADAS-2 tool, and then collect and validate individual patient data. The objectives of the primary analyses will be to assess the diagnostic accuracy of ONSD ultrasonography and to determine a precise cutoff value for detecting raised ICP. Secondly, we will construct a logistic regression model to assess whether patient and study characteristics influence diagnostic accuracy.

DISCUSSION

We believe that this IPD MA will provide the most reliable basis for the assessment of diagnostic accuracy of ONSD ultrasonography for detecting raised ICP and to provide a cutoff value. We also hope that the creation of the ONSD research group will encourage further study.

TRIAL REGISTRATION

PROSPERO registration number: CRD42012003072.

The surgeon's decision as a prognostic factor in a pool of patients with colorectal cancer coming from different institutions

Different pathological and predictive factors are used to stratify patients submitted to radical surgery for colorectal carcinoma. In addition to stage and histotype, the surgeon's technique and decisions also appeared to affect the prognosis. The aim of the present study was to evaluate if the extent of lymphadenectomy was associated with a different long-term outcome in a pool of 117 patients. In particular, in patients classified as Dukes' B, some evidences seem to suggest that the staging procedure depends on a correct surgical lymphadenectomy with a higher risk of understaging colorectal carcinomas when the number of removed nodes is limited. Moreover, the promptness in forwarding patients to the chemotherapist seems to influence the disease-free survival.

Effect of standard total knee arthroplasty surgical dissection on human patellar blood flow in vivo: an investigation using laser Doppler flowmetry

We examined the in vivo alterations of human patellar bone blood flow that occur with surgical dissection of the extensor mechanism during total knee arthroplasty. A laser doppler probe was used to measure central patellar blood flow at baseline after quadriceps tenotomy, after partial fat pad excision, after lateral release, and after completion of the lateral release with superolateral geniculate sacrifice. The initial quadriceps tenotomy and medial arthrotomy decreased patellar vascularity to 60.4% of baseline. Fat pad resection initiated another 10.4% decline. The lateral release resulted in a patellar vascularity that was 43.6% of baseline. Finally, the loss of superolateral geniculate inflow reduced the patellar flow to 30.61% of baseline.

Protective effects of nedocromil sodium on cellular and biohumoral components present in the bronchial alveolar lavage fluid and in peripheral blood in atopic asthmatics

Nedocromil sodium, a disodium salt of a pyroquinolinedicarboxylic acid, raises the bronchial hyperresponsiveness threshold, because it inhibits the mediators released by the various cells, and reduces the involvement and activation of inflammatory cells. The aim of this study was to evaluate the state of activation of the immunocompetent cells and the main chemical mediators present in the bronchoalveolar lavage (BAL) fluid from 10 atopic asthmatic patients, before and after treatment with nedocromil sodium. The following examinations were performed before treatment and after 120 days of therapy with nedocromil sodium at 16 mg/day (two 2-mg puffs x 4): the level of chemical mediators and the state of activation of immunocompetent cells in BAL fluid; immunological analytes in activation of immunocompetent cells in BAL fluid; immunological analytes in peripheral blood; aspecific bronchial challenge test with ultrasonicated bidistilled H2O fog to evaluate variations in the hyperreactivity threshold; questionnaire to determine any adverse effects of treatment (cough, breathlessness, sleep disorders). Our findings demonstrate that nedocromil sodium prevents the release of chemotactic and inflammatory mediators by the effector cells and thus stabilizes microvascular permeability and epithelial damage, so raising the threshold of response to bronchoconstriction stimuli. Lastly, nedocromil sodium is associated with a better preventive therapeutic efficacy and good tolerance and can therefore be suggested as a valid drug to be used in the long-term treatment of bronchial asthma.

[Correlations between the prick test and aspecific bronchial reactivity in atopic patients]

Aspecific bronchial provocation test with Methacholine plays an outstanding role in the diagnostic routine of asthmatic disease, in order to accomplish a correct interpretation of the relation between A.B.I. and bronchial asthma. All researches give a special prominence to the bronchial reactivity distribution among the population, and point out that the distribution curve of response to aspecific challenge shows itself as an unimodal curve, since there is no clinic group (neither that one including subjects defined asthmatic from a clinic or anamnestic point of view) which clearly separates from the rest. A further important consideration indicates that a positive response to the test is not specific of bronchial asthmatic subjects, but it can also occur in patients affected with other pathologies such as chronic bronchitis, allergic rhinitis, and so on. Our study aimed, therefore, to evaluate the correlations occurring between skin sensitivity and aspecific bronchial reactivity in 5 groups of atopic patients (affected with: (1) asthma; (2) asthma + rhinitis; (3) asthma + rhinitis + conjunctivitis; (4) rhinitis + conjunctivitis; (5) rhinitis). In doing such correlations we also considered some other factors like sex, smoking habit, town or country provenance. Sensitiveness, specificity, and predicting value of Prick-test in comparison with Methacholine test have been analysed as well. The results so obtained show that no correlation occurs between Prick-test and Aspecific Bronchial Test in the groups of tested subjects. Test sensitiveness increases in the groups of patients affected with associated pathologies, and depends on factors like sex, smoking habit, town or country provenance.

Nipple discharge: surgical significance

Nipple discharge is an important clinical entity ranking second only to a lump as the most common complaint among 7,588 patients having breast surgery (560/7,588, or 7.4%). In the office and clinic it is even more common, since many patients can be treated medically and do not require an operation. To be significant, a discharge should be true, spontaneous, persistent, and nonlactational. Nipple discharge can be milky, multicolored and sticky, purulent, clear (watery), yellow (serous), pink (serosanguineous), or bloody (sanguineous). Watery, serous, serosanguineous, and sanguineous discharges are surgically significant; while they are most often caused by intraductal papillomas or fibrocystic disease, they can be due to cancer or a precancerous mastopathy. Among 503 patients operated on for one of these types of discharge, 67 (13.3%) had cancer, and 36 (7.2%) had a precancerous mastopathy. Among the 67 patients with cancer, eight (11.9%) had no palpable mass, 11 (16.4%) had negative cytologic findings, and seven (10.4%) had a negative mammogram. The incidence of associated cancers increases when the discharge is, in order of increasing frequency, serous, serosanguineous, sanguineous, or watery, when it is accompanied by a lump, when it is unilateral and from a single duct, when there are positive cytologic or mammographic findings, and when the patient is more than 50 years of age. Milky discharge caused by galactorrhea is treated medically except when caused by a pituitary adenoma. Multicolored sticky discharge due to duct ectasia is also treated medically except in advanced cases. Purulent discharge caused by an abscess requires drainage and a biopsy of the abscess wall. Except in women less than 30 years of age of in those anxious to have children, we advise a complete central duct excision for patients with surgically significant types of discharge. If done carefully, this procedure can yield good cosmetic results.

Breast cancer statistics: use and misuse

Statistics can be manipulated, by using various methods of reporting, to support almost any type of regime in breast cancer. The basis for statistical calculations include: the definition of the population of patients treated, the time used for starting calculations, the exact nature of the treatment used and any adjuvant therapy, the prognostic parameters utilized, the importance of long-term follow-ups, adequate number of cases, therapy standardization and pathological reporting, methods of evaluating survival such as observed or crude, relative and no evidence of disease, methods of calculating observed survival rates such as absolute, actuarial or life-table and Kaplan Meier or product limit, statistical evaluation for planned improvement with acceptable Type I and Type II errors, and the use of arithmetic and logarithmic scales in plotting statistics. Purveyors of innovative methods for the treatment of breast cancer aimed at preserving part or all of the breast as cosmetic alternatives to mastectomy, by limited operations with and without primary radiotherapy, have a most appealing argument to a woman with breast cancer. To determine if such procedures are justifiable alternatives to selective mastectomies and reconstructions, detailed, long-term statistical data on large numbers of cases must be available and end-results comparisons of various therapeutic modalities must be made on the basis of comparable statistical data.

Breast biopsy and guidance for occult lesions

Biopsy and histological examination is the only way of determining with absolute accuracy whether a lesion is benign or malignant, as well as its exact nature and whether it shows any evidence of precancerous changes. Occult malignant lesions, not clinically detectable, may be found by the study of surrounding tissue in the course of the excision of a benign lesion. However, they are most often found by breast x-rays (mammography or xerography) which are done for: the survey of high-risk asymptomatic women; contralateral breast studies; symptomatic breasts without palpable findings; nipple discharge; large pendulous breasts; and multinodular breasts. Biopsies for occult lesions, based on radiographic findings, are recommended for: suspicious calcifications; stellate-shaped masses; breast masses with ill-defined borders or nodular contours; dominant masses; and areas of increased density or distorted breast architecture. In general, biopsy for these lesions is best done under general anesthesia, as an in-patient and as a two-step type of procedure, i.e., the biopsy should be studied by permanent histologic sections before making a final diagnosis. Preoperative localization can be done by measurements, markers, radio-opaque dye injections or by needle localization which we feel is the preferred technique because it is simple and accurate and allows for removal of only a small amount of tissue with better cosmetic results. The advantages and disadvantages of various types of needle localization are discussed and figures are given for 387 needle localizations in which 148 cancers were found (38.2%). Of these cancers, 54.1% were invasive and 45.9% were noninvasive.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular topology and aqueous solubility of aliphatic alcohols

A physically based method for arriving at topological indexes is described. The derived indexes correlate with molecular surface areas and with the molecular connectivity index. The newly derived index seems to account better for the expected distinctions among primary, secondary, and tertiary alcohol aqueous solubilities. This study suggests that the Del Re method for calculating molecular charges and dipole moments also may be used, without appreciable change, to provide estimates of molecular refraction.

Pattern recognition II: Investigation of structure--activity relationships

A simple form of pattern recognition is successfully used to classify a set of structurally diverse therapeutic agents. By using only organic structural information, the major pharmacological classes present were correctly identified and the pharmacologically unrelated compounds were separated out. One technique of factor analysis--principal component analysis--is shown to be readily adaptable in preprocessing the data. Simple graphical representation of the results enables their direct interpretation.

Pattern recognition. Classification of therapeutic agents according to pharmacophores

One of the preprocessing methods used in pattern recognition-factor analysis-is shown to be well suited to the derivation of structure-activity relationships. Applications of the procedure developed are illustrated using sets of compounds which are of accepted therapeutic utility.

Pharmacokinetic model for a primary antibody response

Antigen distribution and clearance studied in vivo may be viewed as a pharmacokinetic problem complicated by the intervention of the immune response. A model characterizing the clearance of the simple antigen phiX174 from the bloodstream of various experimental animals, as well as the subsequent serum antibody response, was developed. The present model is the simplest of the possible models and no doubt will have to be modified when considering more complex antigens, additional distribution modes, and differences in antibody reactivity. For the primary (IgM) immune response, however, early events in the immunological response can be adequately accounted for in a consistent and quantitative manner.