Singlet Fission in Crystalline Organic Materials: Recent Insights and Future Directions

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

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On Future Directions in Pathology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053991 ◽

1982 ◽

Vol 40 ◽

pp. 274-277

Author(s):

Benjamin F. Trump ◽

Irene K. Berezesky ◽

Raymond T. Jones

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Clinical Pathology ◽

Future Directions ◽

Diagnostic Pathology ◽

The Past ◽

Transmission Electron ◽

Organ Systems ◽

The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

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200kv superconducting cryo electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127645 ◽

1987 ◽

Vol 45 ◽

pp. 642-643

Author(s):

M. Iwatsuki ◽

Y. Kokubo ◽

Y. Harada ◽

J. Lehman

Keyword(s):

Electron Microscope ◽

Structure Analysis ◽

Organic Materials ◽

Strong Interactions ◽

Specimen Preparation ◽

Great Effort ◽

Electron Microscopic ◽

Crystal Fields ◽

Special Skill ◽

Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

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STM of freeze-fracture replicas: Problems and promises

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146187 ◽

1993 ◽

Vol 51 ◽

pp. 68-69

Author(s):

J. T. Woodward ◽

J. A. N. Zasadzinski

Keyword(s):

Scanning Tunneling Microscope ◽

Organic Materials ◽

Freeze Fracture ◽

Atomic Resolution ◽

Scanning Tunneling ◽

Tunneling Microscope ◽

Molecular Scale ◽

Organic Surfaces ◽

Metal Layers ◽

Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

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Stabilizing pyritic material

The Paleontological Society Special Publications ◽

10.1017/s2475262200005207 ◽

1989 ◽

Vol 4 ◽

pp. 244-248 ◽

Cited By ~ 2

Author(s):

Donald L. Wolberg

Keyword(s):

Significant Contribution ◽

Organic Materials ◽

Sedimentary Rocks ◽

Iron Sulfides ◽

Decomposition Products ◽

Iron Minerals ◽

Pyrite Formation ◽

Organic Sediments ◽

Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

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Editorial: Proposed future directions of dentistry

Journal of Dental Education ◽

10.1002/j.0022-0337.1974.38.8.tb00809.x ◽

1974 ◽

Vol 38 (8) ◽

pp. 423-424

Author(s):

E Johansen

Keyword(s):

Future Directions

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Meeting the Best Practice for Hearing Aid Verification in Children: Challenges and Future Directions

American Journal of Audiology ◽

10.1044/2019_aja-18-0156 ◽

2019 ◽

Vol 28 (4) ◽

pp. 877-894

Author(s):

Nur Azyani Amri ◽

Tian Kar Quar ◽

Foong Yen Chong

Keyword(s):

Clinical Practice ◽

Hearing Aids ◽

Best Practice ◽

Hearing Aid ◽

Evidence Based ◽

Future Directions ◽

Major Barrier ◽

Klang Valley ◽

Age Range ◽

Fitting Hearing Aids

Purpose This study examined the current pediatric amplification practice with an emphasis on hearing aid verification using probe microphone measurement (PMM), among audiologists in Klang Valley, Malaysia. Frequency of practice, access to PMM system, practiced protocols, barriers, and perception toward the benefits of PMM were identified through a survey. Method A questionnaire was distributed to and filled in by the audiologists who provided pediatric amplification service in Klang Valley, Malaysia. One hundred eight ( N = 108) audiologists, composed of 90.3% women and 9.7% men (age range: 23–48 years), participated in the survey. Results PMM was not a clinical routine practiced by a majority of the audiologists, despite its recognition as the best clinical practice that should be incorporated into protocols for fitting hearing aids in children. Variations in practice existed warranting further steps to improve the current practice for children with hearing impairment. The lack of access to PMM equipment was 1 major barrier for the audiologists to practice real-ear verification. Practitioners' characteristics such as time constraints, low confidence, and knowledge levels were also identified as barriers that impede the uptake of the evidence-based practice. Conclusions The implementation of PMM in clinical practice remains a challenge to the audiology profession. A knowledge-transfer approach that takes into consideration the barriers and involves effective collaboration or engagement between the knowledge providers and potential stakeholders is required to promote the clinical application of evidence-based best practice.

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