Abstract: In order to make an attempt to reduce the size of the laser and to simplify the structure, in a double wavelength laser of the invention, when an optical path switching mirror 3 is located at a position where light is not reflected, emitted light of a laser diode 1 is converted into parallel light with a collimator lens 2, light is collected to an Er: YAG crystal 6 with a collector lens 4 for pumping, light output by the pumping of the Er: YAG crystal 6 is amplified with a total reflective mirror 5 and an output mirror 7 and passes through a folded mirror 8 from the output mirror 7, and light is guided to a light guide unit 10 with a collector lens 9 to be emitted outside, and when the optical path conversion mirror 3 is located at a position where light is reflected, the emitted light of the laser diode 1 is reflected in 90 degrees direction with the optical path switching mirror 3 and is guided to the light guide unit 10 with a collector lens 11 to be emitted outside.

Abstract: An overlock sewing machine which can readily form a rolled seam with no requirement for a complicated tension adjusting operation is disclosed. In this overlock sewing machine, an auxiliary thread tensioner (15) is provided independently of a main thread tensioner (4), providing a lower looper thread (9) with thread tension which is necessary for forming an over-edge chain stitch, in the vicinity thereof. An end cam (25) is provided on a shaft (13) of a dial (12) for feed adjustment, so that an upper pawl (23) rams one portion of the peripheral edge of a tension disc (20) and expands a side which is opposed thereto for canceling tension provision to the lower looper thread (9) passed through tension discs and provides the tension only by the main thread tensioner (4) to carry out an ordinary over-edge chain stitch when a lower pawl (24) is engaged with a high lift part of the end cam (25).

Abstract: An overlock sewing machine which can switch its operation from an ordinary over-edge chain stitch to a rolled seam or vice versa with no requirement for a complicated operation of adjusting thread tension is obtained. This overlock sewing machine is provided with a spring for providing a thread with prescribed tension. The overlock sewing machine is further provided with a switching mechanism for switching the thread tension between that for the rolled seam and that for the over-edge chain stitch by switching the spring between a tensioning state and a non-tensioning state. Thus, the thread tension is readily switched between that for the rolled seam and that for the over-edge chain stitch.

Abstract: Various .beta.,.gamma.-dihydropolyprenyl alcohol derivatives having the formula: ##STR1## wherein n is an integer of 5 to 7 and R is hydrogen, a lower alkyl group or an aliphatic or aromatic acyl group are effective at pritigating stress in animals.

Abstract: Obtained is a thread cutter for a sewing machine which can further readily and reliably cut a needle thread, a looper thread or a chain loop by pushing down a knob without driving the sewing machine. In this thread cutter for a sewing machine, a long groove is formed in a needle plate which is positioned behind a presser foot, and a fixed blade is so provided that its cutting edge is along an edge of the long groove. A movable blade which is pressed against the fixed blade by a plate spring is mounted on a spindle, and the spindle is rotated to vertically move the movable blade when the knob frontwardly projecting from the sewing machine is operated. The thread or the chain loop is cut by the vertical movement of the movable blade in association with the fixed blade.

Abstract: A .beta.,.gamma.-dihydropolyprenyl alcohol derivative having the formula: ##STR1## wherein n is an integer of 5 to 7 and R is hydrogen, a lower alkyl group or an aliphatic or aromatic acyl group, is new and usrful as a prophylactic therapeutic agent for human and animal immuno-deficiency deseases and phylactic agent against human and animal infectious deseases. Another disclosed polyprenyl compound is also useful as the same agent.

Abstract: A novel compound, 3,7,11,15-tetramethyl-2,4,6,10,14-hexadecapentaenoic acid, and a salt thereof are disclosed together with a number of different processes for the preparation of the compound. The uses of the novel compound as an agent for treating papillomata are also disclosed.

Abstract: Skin diseases with keratinization and allergic or inflammatory skin diseases are treated by orally or parenterally administering to an adult human patient from 40 mg to 4 g/day of a polyprenyl compound having the formula (I): ##STR1## in which each of n and m is 0, 1, or 2, n+m is 0, 1 or 2, A is ##STR2## and B is ##STR3## [in which R represents the hydroxyl group, a lower alkoxy group, or ##STR4## (wherein each of R.sub.1 and R.sub.

Abstract: A novel compound, 3,7,11,15-tetramethyl-2,4,6,10,14-hexadecapentaenoic acid, and a salt thereof are disclosed together with a number of different processes for the preparation of the compound. The uses of the novel compound as an anticancer agent are also disclosed.

Abstract: An anti-cancer agent which comprises a polyprenvl compound having the formula (I): ##STR1## in which each of n and m is 0, 1 or 2, n+m is 0, 1 or 2, A is ##STR2## and B is ##STR3## in which R represents the hydroxyl group, a lower alkoxy group, or ##STR4## (wherein each of R.sub.1 and R.sub.

Abstract: A looper for a sewing machine capable of making overlocked stitches has a unitary distal portion which is operable for the selective production of overlocked stitches with one needle and three threads or one needle and two threads. The unitary distal portion of the looper includes an upper looper portion and a spreader portion. A holder is provided in connection with driving means for supporting the looper, and a positioning arrangement is provided to selectively position the unitary distal portion of the looper in a first position for movement along a first path or in a second position for movement along a second path for the selective production of the stitches.

Abstract: A looper changeover device for a sewing maching capable of making overlocked stitches is improved by having a manually operable, rotatable selector mechanism for securing and selectively positioning a looper with respect to a looper holder and a looper driving mechanism between a first position and a second position wherein the looper can be moved along separate paths for the selective production of overlocked stitches with one needle and three threads or one needle and two threads. The rotatable selector mechanism can include a rotatable disk or dial supported by the holder and engaging a portion of the looper for positioning and securing the looper in either of the first and second positions.

Abstract: An alloy of nickel and titanium in the atomic ratio of 49:51 to 56:44 can be prepared at a temperature much lower than the eutectic point of the corresponding alloy. Thus, a green compact of a powdery mixture of the component metals is subjected to a heat treatment under high vacuum first at a rate of temperature elevation of 5.degree. to 30.degree. C./minute up to a temperature of, for example, 600.degree. C. and then at a rate of temperature elevation of at least 40.degree. C./minute up to a temperature of 815.degree.-900.degree. C. The surface of the metal particles is activated at the first stage along with degassing and the surface-activated metal particles are brought into an exothermic reaction at the second stage to cause explosive fusion and alloying.

Abstract: A conjugated polyprenylcarboxylic acid and its derivative having the formula: ##STR1## in which each of n and m is 0, 1 or 2, n+m is 1 or 2, A is ##STR2## and R is the hydroxyl group, a lower alkoxy group or ##STR3## wherein each of R.sub.1 and R.sub.2 represents the hydrogen atom, a lower alkyl group, or an aryl group; provided that R is ##STR4## if A is ##STR5## n is 1 and m is 0.

Abstract: A .beta.,.gamma.-dihydropolyprenyl alcohol derivative having the formula: ##STR1## wherein n is an integer of 5 to 7 and R is hydrogen, a lower alkyl group or an aliphatic or aromatic acyl group, is new and useful as a phylactic agent against human and animal infectious diseases. Other disclosed polyprenyl compounds are also useful as such agents.

Abstract: The polyprenyl compound having the formula: ##STR1## wherein X represents a group of the formula: --CH.dbd.CH--, a group of the formula: ##STR2## or a group of the formula: ##STR3## and Y represents a group of the formula: --COOR.sup.1 in which R.sup.1 represents a hydrogen atom or a lower alkyl group or a group of the formula: ##STR4## in which R.sup.2 represents a hydrogen atom or a lower alkyl group, is new and useful as a medicine.

Abstract: A switching power converter with high conversion efficiency has been found. The converter has a DC power source (1), a switching element (2), a transformer (3) so that said DC power source (1) supplies the primary power to the transformer (3) through the switching element (2). A rectifier and an output filter circuit are provided at the secondary side of the transformer (3). A parallel circuit with a capacitor (12) and a coil (13) is inserted in the primary current path, and a control circuit (14) controls the ON and/or OFF status of said switching element (2) so that the switching element (2) is turned to the ON status when the current in the coil (13) reaches a predetermined value which depends upon the output power of the present power converter, and said switching element (2) is turned to the OFF status after the current in said switching element (2) reaches zero.

Abstract: A link rod connector is formed to have two sections connected by a resilient hinge and each section is provided with a semicylindrical leg portion having a resilient catch. In use, the sections are closed onto each other to retain a link rod therebetween in such a manner that the link rod is rotatable within the sections but cannot be extracted therefrom, and then the cylindrical leg formed by the semicylindrical leg portions is inserted into a hole in a link arm so that the link rod is rotatable with respect thereto.