Micromachining of micro and nano-structured metals

The microstructure of machined metals change near the tool affected zone. This paper presents some new results concerning mirror-like surface cutting of aluminum and copper. The microstructure of aluminum and copper represents the polycrystalline mild metals with face centered cubic (fcc) crystal lattice. The examination of mirror-like surface by optical microscopy, scanning electron microscopy, electron backscattered diffraction (EBSD) and atomic force microscopy show the grain boundaries and twin boundaries, which separates two domains for different crystal orientation. Young’s modulus that depends on orientation can change considerably on these boundaries, consequently the value of elastic deformation of the layer under machined surface. This effect modified the roughness too. Aluminum and copper were cut as “conventional” micro-structured metals used in everyday practice and after so called ECAP process with nano-crystalline structure, for examining effects of crystal size on machinability and surface integrity of machined mirror surfaces. Results of these comparative experiments are discussed in this paper

Micromachining of micro and nano-structured metals

The microstructure of machined metals change near the tool affected zone. This paper presents some new results concerning mirror-like surface cutting of aluminum and copper. The microstructure of aluminum and copper represents the polycrystalline mild metals with face centered cubic (fcc) crystal lattice. The examination of mirror-like surface by optical microscopy, scanning electron microscopy, electron backscattered diffraction (EBSD) and atomic force microscopy show the grain boundaries and twin boundaries, which separates two domains for different crystal orientation. Young’s modulus that depends on orientation can change considerably on these boundaries, consequently the value of elastic deformation of the layer under machined surface. This effect modified the roughness too. Aluminum and copper were cut as “conventional” micro-structured metals used in everyday practice and after so called ECAP process with nano-crystalline structure, for examining effects of crystal size on machinability and surface integrity of machined mirror surfaces. Results of these comparative experiments are discussed in this paper

Mechanisms of manipulation:a systematic review of the literature on immediate anatomical structural or positional changes in response to manually delivered high-velocity, low-amplitude spinal manipulation

Background: Spinal manipulation (SM) has been claimed to change anatomy, either in structure or position, and that these changes may be the cause of clinical improvements. The aim of this systematic review was to evaluate and synthesise the peer-reviewed literature on the current evidence of anatomical changes in response to SM. Methods: The review was registered with PROSPERO (CRD42022304971) and reporting was guided by the standards of the PRISMA Statement. We searched Medline, Embase, CINAHL, AMED, Cochrane Library all databases, PEDro, and the Index to Chiropractic Literature from inception to 11 March 2022 and updated on 06 June 2023. Search terms included manipulation, adjustment, chiropractic, osteopathy, spine and spine-related structures. We included primary research studies that compared outcomes with and without SM regardless of study design. Manipulation was defined as high-velocity, low-amplitude thrust delivered by hand to the spine or directly related joints. Included studies objectively measured a potential change in an anatomical structure or in position. We developed a novel list of methodological quality items in addition to a short, customized list of risk of bias (RoB) items. We used quality and RoB items together to determine whether an article was credible or not credible. We sought differences in outcomes between SM and control groups for randomised controlled trials and crossover studies, and between pre- and post-SM outcomes for other study designs. We reported, in narrative form, whether there was a change or not. Results: The search retrieved 19,572 articles and 20 of those were included for review. Study topics included vertebral position (n = 3) facet joint space (n = 5), spinal stiffness (n = 3), resting muscle thickness (n = 6), intervertebral disc pressure (n = 1), myofascial hysteresis (n = 1), and further damage to already damaged arteries (n = 1). Eight articles were considered credible. The credible articles indicated that lumbar facet joint space increased and spinal stiffness decreased but that the resting muscle thickness did not change. Conclusion: We found few studies on this topic. However, there are two promising areas for future study: facet joint space and spinal stiffness. A research strategy should be developed with funding for high quality research centres

The effectiveness of spinal manipulative therapy procedures for spine pain: Protocol for a systematic review and network meta-analysis

Background: Spinal manipulative therapy (SMT) is a guideline-recommended treatment option for spinal pain. The recommendation is based on multiple systematic reviews. However, these reviews fail to consider that clinical effects may depend on SMT “application procedures” (i.e., how and where SMT is applied). Using network meta-analyses, we aim to investigate which SMT “application procedures” have the greatest magnitude of clinical effectiveness for reducing pain and disability, for any spinal complaint, at short-term and long-term follow-up. We will compare application procedural parameters by classifying the thrust application technique and the application site (patient positioning, assisted, vertebral target, region target, Technique name, forces, and vectors, application site selection approach and rationale) against: 1. Waiting list/no treatment; 2. Sham interventions not resembling SMT (e.g., detuned ultrasound); 3. Sham interventions resembling SMT; 4. Other therapies not recommended in clinical practice guidelines; and 5. Other therapies recommended in clinical practice guidelines. Secondly, we will examine how contextual elements, including procedural fidelity (whether the SMT was delivered as planned) and clinical applicability (whether the SMT is similar to clinical practice) of the SMT. Methods: We will include randomized controlled trials (RCT) found through three search strategies, (i) exploratory, (ii) systematic, and (iii) other known sources. We define SMT as a high-velocity low-amplitude thrust or grade V mobilization. Eligibility is any RCT assessing SMT against any other type of SMT, any other active or sham intervention, or no treatment control on adult patients with pain in any spinal region. The RCTs must report on continuous pain intensity and/or disability outcomes. Two authors will independently review title and abstract screening, full-text screening, and data extraction. Spinal manipulative therapy techniques will be classified according to the technique application and choice of application sites. We will conduct a network-meta analysis using a frequentist approach and multiple subgroup and sensitivity analyses. Discussion: This will be the most extensive review of thrust SMT to date, and will allow us to estimate the importance of different SMT application procedures used in clinical practice and taught across educational settings. Thus, the results are applicable to clinical practice, educational settings, and research studies. PROSPERO registration: CRD42022375836