COLLOIDAL particles of metals and semiconductors have potentially useful optical, optoelectronic and material properties1–4 that derive from their small (nanoscopic) size. These properties might lead to applications including chemical sensors, spectro-scopic enhancers, quantum dot and nanostructure fabrication, and microimaging methods2–4. A great deal of control can now be exercised over the chemical composition, size and polydis-persity1,2 of colloidal particles, and many methods have been developed for assembling them into useful aggregates and materials. Here we describe a method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates. The method involves attaching to the surfaces of two batches of 13-nm gold particles non-complementary DNA oligo-nucleotides capped with thiol groups, which bind to gold. When we add to the solution an oligonucleotide duplex with 'sticky ends' that are complementary to the two grafted sequences, the nanoparticles self-assemble into aggregates. This assembly process can be reversed by thermal denaturation. This strategy should now make it possible to tailor the optical, electronic and structural properties of the colloidal aggregates by using the specificity of DNA interactions to direct the interactions between particles of different size and composition.

A DNA-based Method for Rationally Assembling Nanoparticles Into Macroscopic Materials

http://experimentationlab.berkeley.edu/sites/default/files/AFMImages/butt_AFM.pdf

Force measurements with the atomic force microscope: Technique, interpretation and applications

The large ribosomal subunit catalyzes peptide bond formation and binds initiation, termination, and elongation factors. We have determined the crystal structure of the large ribosomal subunit from Haloarcula marismortui at 2.4 angstrom resolution, and it includes 2833 of the subunit's 3045 nucleotides and 27 of its 31 proteins. The domains of its RNAs all have irregular shapes and fit together in the ribosome like the pieces of a three-dimensional jigsaw puzzle to form a large, monolithic structure. Proteins are abundant everywhere on its surface except in the active site where peptide bond formation occurs and where it contacts the small subunit. Most of the proteins stabilize the structure by interacting with several RNA domains, often using idiosyncratically folded extensions that reach into the subunit's interior.

https://science.sciencemag.org/content/sci/289/5481/905.full.pdf

The complete atomic structure of the large ribosomal subunit at 2.4 A resolution.

The DNA of telomeres--the terminal DNA-protein complexes of chromosomes--differs notably from other DNA sequences in both structure and function. Recent work has highlighted its remarkable mode of synthesis by the ribonucleoprotein reverse transcriptase, telomerase, as well as its ability to form unusual structures in vitro. Moreover, telomere synthesis by telomerase has been shown to be essential for telomere maintenance and long-term viability.

Structure and function of telomeres

Molecular self-assembly presents a `bottom-up' approach to the fabrication of objects specified with nanometre precision. DNA
 molecular structures and intermolecular interactions are particularly
 amenable to the design and synthesis of complex molecular objects. We
 report the design and observation of two-dimensional crystalline forms
 of DNA that self-assemble from synthetic DNA double-crossover
 molecules. Intermolecular interactions between the structural units are
 programmed by the design of `sticky ends' that associate according to
 Watson-Crick complementarity, enabling us to create specific periodic
 patterns on the nanometre scale. The patterned crystals have been
 visualized by atomic force microscopy.

https://issg.cs.duke.edu/courses/spring04/cps296.4/papers/WLWS98.pdf

Design and self-assembly of two-dimensional DNA crystals

Gradual distal fibula lengthening (DFL), in conjunction with other procedures, was used to correct ankle valgus and short fibulae in three pediatric patients with multiple hereditary exostoses (MHE). The average amount of DFL was 15 mm with a mean follow-up of 2.9 years. Final radiographs showed that all three patients had a stable ankle mortise without evidence of talar tilt or widening. In conclusion, gradual DFL has the advantage of restoring anatomy in cases of ankle valgus due to short fibulae and MHE, and may be performed in conjunction with other procedures.

Distraction Osteogenesis of the Fibula to Correct Ankle Valgus in Multiple Hereditary Exostoses.

Verfahren und vorrichtung zur molekularen analyse bei kleinen probenvolumen

Soft-tissue sarcomas (STSs) are a heterogenous group of rare malignancies that have significant lifelong implications. Accepted management options include limb-sparing surgical resection and adjuvant radiation therapy. Here we present the case of a myxoid malignant fibrous histiocytoma, now termed a myxofibrosarcoma, which recurred 21 years after primary surgical resection. To our knowledge, this is the longest documented interval between initial management and recurrence of an STS. Significant changes have been made in classification guidelines and diagnostic methods over this 2-decade period. The pathogenesis of remote recurrence of STSs remains controversial and is discussed in this report.

Biology, classification, and management of recurrent myxofibrosarcoma 21 years after resection.

Auswertung von bindungsaffinitäten durch kraftschichtung und kraftplanung

Introduction Decision aids are effective tools in facilitating patient-centered care and patient involvement in the decision-making process. Given unique barriers to providing patient-centered care for Veterans, implementation of decision aids may improve overall quality of care. We aimed to assess the acceptability and feasibility of video-based and pamphlet-based decision aid use in Veterans with knee osteoarthritis. Materials and Methods Veterans considering treatment for knee osteoarthritis received either an online video-based aid, pamphlet-based aid, or both before their surgical consult. At their visit, patients completed written pre-visit and post-visit questionnaires. The pre-visit questionnaire included questions about the patient’s demographics, decision-making preferences, experiences using the assigned decision aids, and the Hip-Knee Decision Quality Instrument. The post-visit questionnaire assessed the patient’s overall experience with the decision-making process and how use of the decision aid influenced their discussion with the physician. Results All 16 patients who received the pamphlet-based aid reviewed the decision aid before their visit, compared to only five of the 12 patients who received the video-based aid. Thirteen of 20 patients indicated that they preferred to share treatment decision-making with their physician. Seventeen of 20 patients believed they would feel comfortable questioning the treatment recommendation of their surgeon after decision aid use. Most patients reported a positive experience using their decision aid, regardless of modality, and found it easily comprehensible and useful in visit preparation. A preference for a pamphlet-based aid was expressed by the majority of patients. Conclusion Veterans considering treatment for knee osteoarthritis are well prepared to engage in a patient-centered care experience. Most patients preferred sharing the decision-making process with their physician and felt comfortable questioning them about treatment recommendations. Decision aids helped Veterans feel more informed about their treatment options and improved engagement and discussion with their physician. Pamphlet-based aids were utilized more reliably than video-based aids.

Eric Henderson

Papers

Distraction Osteogenesis of the Fibula to Correct Ankle Valgus in Multiple Hereditary Exostoses.

Verfahren und vorrichtung zur molekularen analyse bei kleinen probenvolumen

Biology, classification, and management of recurrent myxofibrosarcoma 21 years after resection.

Auswertung von bindungsaffinitäten durch kraftschichtung und kraftplanung

Acceptability and Feasibility of Delivering Decision Aids to Veterans for Management of Knee Osteoarthritis – A Pilot Study